introduce lifetime of body

return used contacts from push_solve
Delete Body.acceleration Field (#30 )
2026-01-27 10:35:32 -08:00 · 2026-01-27 09:28:26 -08:00 · 2026-01-27 17:08:08 +00:00 · 2026-01-27 07:58:18 -08:00 · 2026-01-27 07:46:17 -08:00 · 2026-01-27 07:38:45 -08:00
23 changed files with 452 additions and 12829 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3904,7 +3904,6 @@ dependencies = [
 "arrayvec",
 "glam",
 "id",
- "mlua",
 "strafesnet_common",
 ]

--- a/engine/graphics/src/graphics.rs
+++ b/engine/graphics/src/graphics.rs
@@ -909,7 +909,7 @@ impl GraphicsState{

 		// update rotation
 		let camera_uniforms=self.camera.to_uniform_data(
-			frame_state.body.extrapolated_position(frame_state.time).map(Into::<f32>::into).to_array().into(),
+			frame_state.trajectory.extrapolated_position(frame_state.time).map(Into::<f32>::into).to_array().into(),
 			frame_state.camera.simulate_move_angles(glam::IVec2::ZERO)
 		);
 		self.staging_belt
--- a/engine/physics/Cargo.toml
+++ b/engine/physics/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2024"
 arrayvec = "0.7.6"
 glam = "0.30.0"
 id = { version = "0.1.0", registry = "strafesnet" }
-mlua = { version = "0.11.5", features = ["luau"] }
 strafesnet_common = { path = "../../lib/common", registry = "strafesnet" }

 [lints]
--- a/engine/physics/src/body.rs
+++ b/engine/physics/src/body.rs
@@ -2,12 +2,19 @@ use strafesnet_common::aabb;
 use strafesnet_common::integer::{self,vec3,Time,Planar64,Planar64Vec3};
 #[derive(Clone,Copy,Debug,Hash)]
 pub struct Body<T>{
-	pub position:Planar64Vec3,//I64 where 2^32 = 1 u
-	pub velocity:Planar64Vec3,//I64 where 2^32 = 1 u/s
-	pub acceleration:Planar64Vec3,//I64 where 2^32 = 1 u/s/s
-	pub time:Time<T>,//nanoseconds x xxxxD!
+	pub position:Planar64Vec3,
+	pub velocity:Planar64Vec3,
+	pub time:Time<T>,
 }
-impl<T> std::ops::Neg for Body<T>{
+#[derive(Clone,Copy,Debug,Hash)]
+pub struct Trajectory<'a,T>{
+	pub position:Planar64Vec3,
+	pub velocity:Planar64Vec3,
+	pub acceleration:Planar64Vec3,
+	pub time:Time<T>,
+	lifetime:core::marker::PhantomData<&'a Body<T>>,
+}
+impl<T> std::ops::Neg for Trajectory<'_,T>{
 	type Output=Self;
 	fn neg(self)->Self::Output{
 		Self{
@@ -15,23 +22,52 @@ impl<T> std::ops::Neg for Body<T>{
 			velocity:-self.velocity,
 			acceleration:self.acceleration,
 			time:-self.time,
+			lifetime:core::marker::PhantomData,
 		}
 	}
 }
-impl<T:Copy> std::ops::Neg for &Body<T>{
-	type Output=Body<T>;
+impl<'a,T:Copy> std::ops::Neg for &Trajectory<'a,T>{
+	type Output=Trajectory<'a,T>;
 	fn neg(self)->Self::Output{
-		Body{
+		Trajectory{
 			position:self.position,
 			velocity:-self.velocity,
 			acceleration:self.acceleration,
 			time:-self.time,
+			lifetime:core::marker::PhantomData,
 		}
 	}
 }

 impl<T> Body<T>
 	where Time<T>:Copy,
+{
+	pub const ZERO:Self=Self::new(vec3::zero(),vec3::zero(),Time::ZERO);
+	pub const fn new(position:Planar64Vec3,velocity:Planar64Vec3,time:Time<T>)->Self{
+		Self{
+			position,
+			velocity,
+			time,
+		}
+	}
+	pub const fn with_acceleration<'a>(&'a self,acceleration:Planar64Vec3)->Trajectory<'a,T>{
+		let Body{
+			position,
+			velocity,
+			time,
+		}=*self;
+		Trajectory{
+			position,
+			velocity,
+			acceleration,
+			time,
+			lifetime:core::marker::PhantomData,
+		}
+	}
+}
+
+impl<T> Trajectory<'_,T>
+	where Time<T>:Copy,
 {
 	pub const ZERO:Self=Self::new(vec3::zero(),vec3::zero(),vec3::zero(),Time::ZERO);
 	pub const fn new(position:Planar64Vec3,velocity:Planar64Vec3,acceleration:Planar64Vec3,time:Time<T>)->Self{
@@ -40,15 +76,17 @@ impl<T> Body<T>
 			velocity,
 			acceleration,
 			time,
+			lifetime:core::marker::PhantomData,
 		}
 	}
-	pub const fn relative_to<'a>(&'a self,body0:&'a Body<T>)->VirtualBody<'a,T>{
+	pub fn relative_to(&self,trj0:&Self,time:Time<T>)->Self{
 		//(p0,v0,a0,t0)
 		//(p1,v1,a1,t1)
-		VirtualBody{
-			body0,
-			body1:self,
-		}
+		Trajectory::new(
+			self.extrapolated_position(time)-trj0.extrapolated_position(time),
+			self.extrapolated_velocity(time)-trj0.extrapolated_velocity(time),
+			self.acceleration-trj0.acceleration,
+			time)
 	}
 	pub fn extrapolated_position(&self,time:Time<T>)->Planar64Vec3{
 		let dt=time-self.time;
@@ -60,10 +98,12 @@ impl<T> Body<T>
 		let dt=time-self.time;
 		self.velocity+(self.acceleration*dt).map(|elem|elem.divide().clamp_1())
 	}
-	pub fn advance_time(&mut self,time:Time<T>){
-		self.position=self.extrapolated_position(time);
-		self.velocity=self.extrapolated_velocity(time);
-		self.time=time;
+	pub fn extrapolated_body(&self,time:Time<T>)->Body<T>{
+		Body::new(
+			self.extrapolated_position(time),
+			self.extrapolated_velocity(time),
+			time,
+		)
 	}
 	pub fn extrapolated_position_ratio_dt<Num,Den,N1,D1,N2,N3,D2,N4,T1>(&self,dt:integer::Ratio<Num,Den>)->Planar64Vec3
 		where
@@ -101,10 +141,12 @@ impl<T> Body<T>
 		// a*dt + v
 		self.acceleration.map(|elem|(dt*elem).divide().clamp())+self.velocity
 	}
-	pub fn advance_time_ratio_dt(&mut self,dt:crate::model::GigaTime){
-		self.position=self.extrapolated_position_ratio_dt(dt);
-		self.velocity=self.extrapolated_velocity_ratio_dt(dt);
-		self.time+=dt.into();
+	pub fn extrapolated_body_ratio_dt(&self,dt:crate::model::GigaTime)->Body<T>{
+		Body::new(
+			self.extrapolated_position_ratio_dt(dt),
+			self.extrapolated_velocity_ratio_dt(dt),
+			self.time+dt.into(),
+		)
 	}
 	pub fn infinity_dir(&self)->Option<Planar64Vec3>{
 		if self.velocity==vec3::zero(){
@@ -144,28 +186,12 @@ impl<T> Body<T>

 }
 impl<T> std::fmt::Display for Body<T>{
+	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
+		write!(f,"p({}) v({}) t({})",self.position,self.velocity,self.time)
+	}
+}
+impl<T> std::fmt::Display for Trajectory<'_,T>{
 	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
 		write!(f,"p({}) v({}) a({}) t({})",self.position,self.velocity,self.acceleration,self.time)
 	}
 }
-
-pub struct VirtualBody<'a,T>{
-	body0:&'a Body<T>,
-	body1:&'a Body<T>,
-}
-impl<T> VirtualBody<'_,T>
-	where Time<T>:Copy,
-{
-	pub fn extrapolated_position(&self,time:Time<T>)->Planar64Vec3{
-		self.body1.extrapolated_position(time)-self.body0.extrapolated_position(time)
-	}
-	pub fn extrapolated_velocity(&self,time:Time<T>)->Planar64Vec3{
-		self.body1.extrapolated_velocity(time)-self.body0.extrapolated_velocity(time)
-	}
-	pub fn acceleration(&self)->Planar64Vec3{
-		self.body1.acceleration-self.body0.acceleration
-	}
-	pub fn body(&self,time:Time<T>)->Body<T>{
-		Body::new(self.extrapolated_position(time),self.extrapolated_velocity(time),self.acceleration(),time)
-	}
-}
--- a/engine/physics/src/face_crawler.rs
+++ b/engine/physics/src/face_crawler.rs
@@ -1,6 +1,6 @@
 use crate::model::{into_giga_time,GigaTime,FEV,MeshQuery,DirectedEdge};
 use strafesnet_common::integer::{Fixed,Ratio,vec3::Vector3};
-use crate::physics::{Time,Body};
+use crate::physics::{Time,Trajectory};

 use core::ops::Bound;

@@ -74,7 +74,7 @@ impl<F:Copy,M:MeshQuery<Normal=Vector3<F>,Offset=Fixed<4,128>>> FEV<M>
 		<F as core::ops::Mul<Fixed<1,32>>>::Output:core::iter::Sum,
 		M::Offset:core::ops::Sub<<F as std::ops::Mul<Fixed<1,32>>>::Output>,
 {
-	fn next_transition(&self,mesh:&M,body:&Body,lower_bound:Bound<GigaTime>,mut upper_bound:Bound<GigaTime>)->Transition<M>{
+	fn next_transition(&self,mesh:&M,trajectory:&Trajectory,lower_bound:Bound<GigaTime>,mut upper_bound:Bound<GigaTime>)->Transition<M>{
 		//conflicting derivative means it crosses in the wrong direction.
 		//if the transition time is equal to an already tested transition, do not replace the current best.
 		let mut best_transition=Transition::Miss;
@@ -86,8 +86,8 @@ impl<F:Copy,M:MeshQuery<Normal=Vector3<F>,Offset=Fixed<4,128>>> FEV<M>
 				let (n,d)=mesh.face_nd(face_id);
 				//TODO: use higher precision d value?
 				//use the mesh transform translation instead of baking it into the d value.
-				for dt in Fixed::<4,128>::zeroes2((n.dot(body.position)-d)*2,n.dot(body.velocity)*2,n.dot(body.acceleration)){
-					if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(body.extrapolated_velocity_ratio_dt(dt)).is_negative(){
+				for dt in Fixed::<4,128>::zeroes2((n.dot(trajectory.position)-d)*2,n.dot(trajectory.velocity)*2,n.dot(trajectory.acceleration)){
+					if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(trajectory.extrapolated_velocity_ratio_dt(dt)).is_negative(){
 						upper_bound=Bound::Included(dt);
 						best_transition=Transition::Hit(face_id,dt);
 						break;
@@ -101,8 +101,8 @@ impl<F:Copy,M:MeshQuery<Normal=Vector3<F>,Offset=Fixed<4,128>>> FEV<M>
 					//WARNING: d is moved out of the *2 block because of adding two vertices!
 					//WARNING: precision is swept under the rug!
 					//wrap for speed
-					for dt in Fixed::<4,128>::zeroes2(n.dot(body.position*2-(mesh.vert(v0)+mesh.vert(v1))).wrap_4(),n.dot(body.velocity).wrap_4()*2,n.dot(body.acceleration).wrap_4()){
-						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(body.extrapolated_velocity_ratio_dt(dt)).is_negative(){
+					for dt in Fixed::<4,128>::zeroes2(n.dot(trajectory.position*2-(mesh.vert(v0)+mesh.vert(v1))).wrap_4(),n.dot(trajectory.velocity).wrap_4()*2,n.dot(trajectory.acceleration).wrap_4()){
+						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(trajectory.extrapolated_velocity_ratio_dt(dt)).is_negative(){
 							upper_bound=Bound::Included(dt);
 							best_transition=Transition::Next(FEV::Edge(directed_edge_id.as_undirected()),dt);
 							break;
@@ -117,15 +117,15 @@ impl<F:Copy,M:MeshQuery<Normal=Vector3<F>,Offset=Fixed<4,128>>> FEV<M>
 				let &[ev0,ev1]=edge_verts.as_ref();
 				let (v0,v1)=(mesh.vert(ev0),mesh.vert(ev1));
 				let edge_n=v1-v0;
-				let delta_pos=body.position*2-(v0+v1);
+				let delta_pos=trajectory.position*2-(v0+v1);
 				for (i,&edge_face_id) in mesh.edge_faces(edge_id).as_ref().iter().enumerate(){
 					let face_n=mesh.face_nd(edge_face_id).0;
 					//edge_n gets parity from the order of edge_faces
 					let n=face_n.cross(edge_n)*((i as i64)*2-1);
 					//WARNING yada yada d *2
 					//wrap for speed
-					for dt in Fixed::<4,128>::zeroes2(n.dot(delta_pos).wrap_4(),n.dot(body.velocity).wrap_4()*2,n.dot(body.acceleration).wrap_4()){
-						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(body.extrapolated_velocity_ratio_dt(dt)).is_negative(){
+					for dt in Fixed::<4,128>::zeroes2(n.dot(delta_pos).wrap_4(),n.dot(trajectory.velocity).wrap_4()*2,n.dot(trajectory.acceleration).wrap_4()){
+						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(trajectory.extrapolated_velocity_ratio_dt(dt)).is_negative(){
 							upper_bound=Bound::Included(dt);
 							best_transition=Transition::Next(FEV::Face(edge_face_id),dt);
 							break;
@@ -136,8 +136,8 @@ impl<F:Copy,M:MeshQuery<Normal=Vector3<F>,Offset=Fixed<4,128>>> FEV<M>
 				for (i,&vert_id) in edge_verts.as_ref().iter().enumerate(){
 					//vertex normal gets parity from vert index
 					let n=edge_n*(1-2*(i as i64));
-					for dt in Fixed::<2,64>::zeroes2((n.dot(body.position-mesh.vert(vert_id)))*2,n.dot(body.velocity)*2,n.dot(body.acceleration)){
-						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(body.extrapolated_velocity_ratio_dt(dt)).is_negative(){
+					for dt in Fixed::<2,64>::zeroes2((n.dot(trajectory.position-mesh.vert(vert_id)))*2,n.dot(trajectory.velocity)*2,n.dot(trajectory.acceleration)){
+						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(trajectory.extrapolated_velocity_ratio_dt(dt)).is_negative(){
 							let dt=Ratio::new(dt.num.widen_4(),dt.den.widen_4());
 							upper_bound=Bound::Included(dt);
 							best_transition=Transition::Next(FEV::Vert(vert_id),dt);
@@ -152,8 +152,8 @@ impl<F:Copy,M:MeshQuery<Normal=Vector3<F>,Offset=Fixed<4,128>>> FEV<M>
 				for &directed_edge_id in mesh.vert_edges(vert_id).as_ref(){
 					//edge is directed away from vertex, but we want the dot product to turn out negative
 					let n=-mesh.directed_edge_n(directed_edge_id);
-					for dt in Fixed::<2,64>::zeroes2((n.dot(body.position-mesh.vert(vert_id)))*2,n.dot(body.velocity)*2,n.dot(body.acceleration)){
-						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(body.extrapolated_velocity_ratio_dt(dt)).is_negative(){
+					for dt in Fixed::<2,64>::zeroes2((n.dot(trajectory.position-mesh.vert(vert_id)))*2,n.dot(trajectory.velocity)*2,n.dot(trajectory.acceleration)){
+						if low(&lower_bound,&dt)&&upp(&dt,&upper_bound)&&n.dot(trajectory.extrapolated_velocity_ratio_dt(dt)).is_negative(){
 							let dt=Ratio::new(dt.num.widen_4(),dt.den.widen_4());
 							upper_bound=Bound::Included(dt);
 							best_transition=Transition::Next(FEV::Edge(directed_edge_id.as_undirected()),dt);
@@ -166,11 +166,11 @@ impl<F:Copy,M:MeshQuery<Normal=Vector3<F>,Offset=Fixed<4,128>>> FEV<M>
 		}
 		best_transition
 	}
-	pub fn crawl(mut self,mesh:&M,relative_body:&Body,lower_bound:Bound<&Time>,upper_bound:Bound<&Time>)->CrawlResult<M>{
-		let mut lower_bound=lower_bound.map(|&t|into_giga_time(t,relative_body.time));
-		let upper_bound=upper_bound.map(|&t|into_giga_time(t,relative_body.time));
+	pub fn crawl(mut self,mesh:&M,trajectory:&Trajectory,lower_bound:Bound<&Time>,upper_bound:Bound<&Time>)->CrawlResult<M>{
+		let mut lower_bound=lower_bound.map(|&t|into_giga_time(t,trajectory.time));
+		let upper_bound=upper_bound.map(|&t|into_giga_time(t,trajectory.time));
 		for _ in 0..20{
-			match self.next_transition(mesh,relative_body,lower_bound,upper_bound){
+			match self.next_transition(mesh,trajectory,lower_bound,upper_bound){
 				Transition::Miss=>return CrawlResult::Miss(self),
 				Transition::Next(next_fev,next_time)=>(self,lower_bound)=(next_fev,Bound::Included(next_time)),
 				Transition::Hit(face,time)=>return CrawlResult::Hit(face,time),
--- a/engine/physics/src/lib.rs
+++ b/engine/physics/src/lib.rs
@@ -3,7 +3,6 @@ mod face_crawler;
 mod model;
 mod push_solve;
 mod minimum_difference;
-mod minimum_difference_lua;

 pub mod physics;

--- a/engine/physics/src/minimum_difference.rs
+++ b/engine/physics/src/minimum_difference.rs
@@ -10,7 +10,7 @@ use crate::model::{MinkowskiMesh,MinkowskiVert};
 // written by Trey Reynolds in 2021

 type Simplex<const N:usize,Vert>=[Vert;N];
-#[derive(Clone,Copy,Debug)]
+#[derive(Clone,Copy)]
 enum Simplex1_3<Vert>{
 	Simplex1(Simplex<1,Vert>),
 	Simplex2(Simplex<2,Vert>),
@@ -136,15 +136,12 @@ fn reduce1<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduced<M::Vert>{
-	println!("reduce1");
 	// --debug.profilebegin("reduceSimplex0")
 	// local a = a1 - a0
 	let p0=mesh.vert(v0);

-	println!("p0={p0}");
 	// local p = -a
 	let p=-(p0+point);
-	println!("p={p}");

 	// local direction = p
 	let mut dir=p;
@@ -168,7 +165,6 @@ fn reduce2<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduced<M::Vert>{
-	println!("reduce2");
 	// --debug.profilebegin("reduceSimplex1")
 	// local a = a1 - a0
 	// local b = b1 - b0
@@ -226,7 +222,6 @@ fn reduce3<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduced<M::Vert>{
-	println!("reduce3");
 	// --debug.profilebegin("reduceSimplex2")
 	// local a = a1 - a0
 	// local b = b1 - b0
@@ -336,7 +331,6 @@ fn reduce4<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduce<M::Vert>{
-	println!("reduce4");
 	// --debug.profilebegin("reduceSimplex3")
 	// local a = a1 - a0
 	// local b = b1 - b0
@@ -355,10 +349,6 @@ fn reduce4<M:MeshQuery>(
 	let mut u=p1-p0;
 	let mut v=p2-p0;
 	let w=p3-p0;
-	println!("p={p}");
-	println!("u={u}");
-	println!("v={v}");
-	println!("w={w}");

 	// local uv = u:Cross(v)
 	// local vw = v:Cross(w)
@@ -429,28 +419,20 @@ fn reduce4<M:MeshQuery>(
 	let pv=p.cross(v);
 	let uv_up=uv.dot(up);
 	let uv_pv=uv.dot(pv);
-	println!("up={up}");
-	println!("pv={pv}");
-	println!("uv_up={uv_up}");
-	println!("uv_pv={uv_pv}");

 	// if uv_up >= 0 and uv_pv >= 0 then
 	if !uv_up.is_negative()&&!uv_pv.is_negative(){
 		// local direction = uvw < 0 and uv or -uv
 		// return direction, a0, a1, b0, b1, c0, c1
-		if uv_w.is_negative(){
-			println!("a");
-			return Reduce::Reduced(Reduced{
-				dir:narrow_dir2(uv),
-				simplex:Simplex1_3::Simplex3([v0,v1,v2]),
-			});
+		let dir=if uv_w.is_negative(){
+			narrow_dir2(uv)
 		}else{
-			println!("b");
-			return Reduce::Reduced(Reduced{
-				dir:narrow_dir2(-uv),
-				simplex:Simplex1_3::Simplex3([v0,v1,v2]),
-			});
-		}
+			narrow_dir2(-uv)
+		};
+		return Reduce::Reduced(Reduced{
+			dir,
+			simplex:Simplex1_3::Simplex3([v0,v1,v2]),
+		});
 	}

 	// local u_u = u:Dot(u)
@@ -482,22 +464,17 @@ fn reduce4<M:MeshQuery>(
 		if direction==vec3::zero(){
 			// direction = uvw < 0 and uv or -uv
 			// return direction, a0, a1, b0, b1
-			if uv_w.is_negative(){
-				println!("c");
-				return Reduce::Reduced(Reduced{
-					dir:narrow_dir2(uv),
-					simplex:Simplex1_3::Simplex2([v0,v1]),
-				});
+			let dir=if uv_w.is_negative(){
+				narrow_dir2(uv)
 			}else{
-				println!("d");
-				return Reduce::Reduced(Reduced{
-					dir:narrow_dir2(-uv),
-					simplex:Simplex1_3::Simplex2([v0,v1]),
-				});
-			}
+				narrow_dir2(-uv)
+			};
+			return Reduce::Reduced(Reduced{
+				dir,
+				simplex:Simplex1_3::Simplex2([v0,v1]),
+			});
 		}

-		println!("e");
 		// return direction, a0, a1, b0, b1
 		return Reduce::Reduced(Reduced{
 			dir:narrow_dir3(direction),
@@ -510,22 +487,17 @@ fn reduce4<M:MeshQuery>(
 	// if direction.magnitude == 0 then
 	if dir==vec3::zero(){
 		// direction = uvw < 0 and uv or -uv
-		if uv_w.is_negative(){
-			println!("f");
-			return Reduce::Reduced(Reduced{
-				dir:narrow_dir2(uv),
-				simplex:Simplex1_3::Simplex1([v0]),
-			});
+		let dir=if uv_w.is_negative(){
+			narrow_dir2(uv)
 		}else{
-			println!("g");
-			return Reduce::Reduced(Reduced{
-				dir:narrow_dir2(-uv),
-				simplex:Simplex1_3::Simplex1([v0]),
-			});
-		}
+			narrow_dir2(-uv)
+		};
+		return Reduce::Reduced(Reduced{
+			dir,
+			simplex:Simplex1_3::Simplex1([v0]),
+		});
 	}

-	println!("h");
 	// return direction, a0, a1
 	Reduce::Reduced(Reduced{
 		dir,
@@ -686,7 +658,7 @@ impl<M:MeshQuery,C:Contains> EVFinder<'_,M,C>{
 		}
 	}
 }
-/// This function drops a vertex down to an edge or a face if the path from infinity did not cross any vertex-edge boundaries but the point is supposed to have already crossed a boundary down from a vertex
+/// This function hops along parallel vertices until it finds the EV which contains the closest point to `point`.
 fn crawl_to_closest_ev<M:MeshQuery>(mesh:&M,simplex:Simplex<2,M::Vert>,point:Planar64Vec3)->EV<M>{
 	// naively start at the closest vertex
 	// the closest vertex is not necessarily the one with the fewest boundary hops
@@ -704,7 +676,7 @@ fn crawl_to_closest_ev<M:MeshQuery>(mesh:&M,simplex:Simplex<2,M::Vert>,point:Pla
 	finder.crawl_boundaries(vert_id,point)
 }

-/// This function drops a vertex down to an edge or a face if the path from infinity did not cross any vertex-edge boundaries but the point is supposed to have already crossed a boundary down from a vertex
+/// This function hops along connected vertices until it finds the FEV which contains the closest point to `point`.
 fn crawl_to_closest_fev<'a>(mesh:&MinkowskiMesh<'a>,simplex:Simplex<3,MinkowskiVert>,point:Planar64Vec3)->FEV::<MinkowskiMesh<'a>>{
 	// naively start at the closest vertex
 	// the closest vertex is not necessarily the one with the fewest boundary hops
@@ -752,30 +724,18 @@ fn crawl_to_closest_fev<'a>(mesh:&MinkowskiMesh<'a>,simplex:Simplex<3,MinkowskiV
 	}
 }

-#[derive(Debug)]
-pub struct InfiniteLoop;
-pub fn closest_fev_not_inside<'a>(mesh:&MinkowskiMesh<'a>,point:Planar64Vec3)->Result<Option<FEV<MinkowskiMesh<'a>>>,InfiniteLoop>{
-	println!("=== LUA ===");
-	let (hits,_details)=crate::minimum_difference_lua::minimum_difference_details(mesh,point).unwrap();
-	println!("=== RUST ===");
-	let closest_fev_not_inside=closest_fev_not_inside_inner(mesh,point).unwrap();
-	assert_eq!(hits,closest_fev_not_inside.is_none(),"algorithms disagree");
-	Ok(closest_fev_not_inside)
-}
-
-pub fn closest_fev_not_inside_inner<'a>(mesh:&MinkowskiMesh<'a>,point:Planar64Vec3)->Result<Option<FEV<MinkowskiMesh<'a>>>,InfiniteLoop>{
+pub fn closest_fev_not_inside<'a>(mesh:&MinkowskiMesh<'a>,point:Planar64Vec3)->Option<FEV<MinkowskiMesh<'a>>>{
 	const ENABLE_FAST_FAIL:bool=false;
 	// TODO: remove mesh negation
 	minimum_difference::<ENABLE_FAST_FAIL,_,_>(&-mesh,point,
 		// on_exact
 		|is_intersecting,simplex|{
-			println!("on_exact simplex={simplex:?}");
 			if is_intersecting{
-				return Ok(None);
+				return None;
 			}
 			// Convert simplex to FEV
 			// Vertices must be inverted since the mesh is inverted
-			Ok(Some(match simplex{
+			Some(match simplex{
 				Simplex1_3::Simplex1([v0])=>FEV::Vert(-v0),
 				Simplex1_3::Simplex2([v0,v1])=>{
 					// invert
@@ -790,18 +750,17 @@ pub fn closest_fev_not_inside_inner<'a>(mesh:&MinkowskiMesh<'a>,point:Planar64Ve
 					// return E or V in edge cases but I don't think that will break the face crawler
 					crawl_to_closest_fev(mesh,[v0,v1,v2],point)
 				},
-			}))
+			})
 		},
 		// on_escape
 		|_simplex|{
 			// intersection is guaranteed at this point
 			// local norm, dist, u0, u1, v0, v1, w0, w1 = expand(queryP, queryQ, a0, a1, b0, b1, c0, c1, d0, d1, 1e-5)
 			// let simplex=refine_to_exact(mesh,simplex);
-			Ok(None)
+			None
 		},
 		// fast_fail value is irrelevant and will never be returned!
-		||unreachable!(),
-		||Err(InfiniteLoop),
+		||unreachable!()
 	)
 }

@@ -819,9 +778,7 @@ pub fn contains_point(mesh:&MinkowskiMesh<'_>,point:Planar64Vec3)->bool{
 			true
 		},
 		// fast_fail value
-		||false,
-		// infinite loop
-		||false,
+		||false
 	)
 }

@@ -836,7 +793,6 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 	on_exact:impl FnOnce(bool,Simplex1_3<M::Vert>)->T,
 	on_escape:impl FnOnce(Simplex<4,M::Vert>)->T,
 	on_fast_fail:impl FnOnce()->T,
-	on_infinite_loop:impl FnOnce()->T,
 )->T{
 	// local initialAxis = queryQ() - queryP()
 	// local new_point_p = queryP(initialAxis)
@@ -847,7 +803,6 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 	if initial_axis==vec3::zero(){
 		initial_axis=choose_any_direction();
 	}
-	println!("initial_axis={initial_axis}");
 	let last_point=mesh.farthest_vert(-initial_axis);
 	// this represents the 'a' value in the commented code
 	let mut last_pos=mesh.vert(last_point);
@@ -855,9 +810,7 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(

 	// exitRadius = testIntersection and 0 or exitRadius or 1/0
 	// for _ = 1, 100 do
-	for _ in 0..100{
-		println!("direction={direction}");
-
+	loop{
 		// new_point_p = queryP(-direction)
 		// new_point_q = queryQ(direction)
 		// local next_point = new_point_q - new_point_p
@@ -865,11 +818,7 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 		let next_pos=mesh.vert(next_point);

 		// if -direction:Dot(next_point) > (exitRadius + radiusP + radiusQ)*direction.magnitude then
-		let d=direction.dot(next_pos+point);
-		let fast_fail=d.is_negative();
-		println!("ENABLE_FAST_FAIL={ENABLE_FAST_FAIL} fast_fail={fast_fail} next_point={} dot={d}",next_pos+point);
-		if ENABLE_FAST_FAIL&&fast_fail{
-			println!("on_fast_fail");
+		if ENABLE_FAST_FAIL&&direction.dot(next_pos+point).is_negative(){
 			return on_fast_fail();
 		}

@@ -878,11 +827,8 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 		// if
 		// 	direction:Dot(next_point - a) <= 0 or
 		// 	absDet(next_point, a, b, c) < 1e-6
-		let cond1=!direction.dot(next_pos-last_pos).is_positive();
-		let cond2=simplex_big.det_is_zero(mesh);
-		println!("cond1={cond1} cond2={cond2}");
-		if cond1||cond2{
-			println!("on_exact");
+		if !direction.dot(next_pos-last_pos).is_positive()
+		||simplex_big.det_is_zero(mesh){
 			// Found enough information to compute the exact closest point.
 			// local norm = direction.unit
 			// local dist = a:Dot(norm)
@@ -895,7 +841,6 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 		match simplex_big.reduce(mesh,point){
 			// if a and b and c and d then
 			Reduce::Escape(simplex)=>{
-				println!("on_escape");
 				// Enough information to conclude that the meshes are intersecting.
 				// Topology information is computed if needed.
 				return on_escape(simplex);
@@ -909,7 +854,6 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 		// next loop this will be a
 		last_pos=next_pos;
 	}
-	on_infinite_loop()
 }

 #[cfg(test)]
@@ -931,8 +875,7 @@ mod test{
 				true
 			},
 			// fast_fail value
-			||false,
-			||false,
+			||false
 		)
 	}

--- a/engine/physics/src/minimum_difference_lua.rs
+++ b/engine/physics/src/minimum_difference_lua.rs
@@ -1,173 +0,0 @@
-use mlua::{Lua,FromLuaMulti,IntoLuaMulti,Function,Result as LuaResult,Vector};
-use strafesnet_common::integer::{Planar64,Planar64Vec3,FixedFromFloatError};
-
-use crate::model::{MeshQuery,MinkowskiMesh};
-
-pub fn contains_point(
-	mesh:&MinkowskiMesh,
-	point:Planar64Vec3,
-)->LuaResult<bool>{
-	Ok(minimum_difference(mesh,point,true)?.hits)
-}
-pub fn minimum_difference_details(
-	mesh:&MinkowskiMesh,
-	point:Planar64Vec3,
-)->LuaResult<(bool,Option<Details>)>{
-	let md=minimum_difference(mesh,point,false)?;
-	Ok((md.hits,md.details))
-}
-fn p64v3(v:Vector)->Result<Planar64Vec3,FixedFromFloatError>{
-	Ok(Planar64Vec3::new([
-		v.x().try_into()?,
-		v.y().try_into()?,
-		v.z().try_into()?,
-	]))
-}
-fn vec(v:Planar64Vec3)->Vector{
-	Vector::new(v.x.into(),v.y.into(),v.z.into())
-}
-struct MinimumDifference{
-	hits:bool,
-	details:Option<Details>
-}
-pub struct Details{
-	pub distance:Planar64,
-	pub p_pos:Planar64Vec3,
-	pub p_norm:Planar64Vec3,
-	pub q_pos:Planar64Vec3,
-	pub q_norm:Planar64Vec3,
-}
-impl FromLuaMulti for MinimumDifference{
-	fn from_lua_multi(mut values:mlua::MultiValue,_lua:&Lua)->LuaResult<Self>{
-		match values.make_contiguous(){
-			&mut [
-				mlua::Value::Boolean(hits),
-				mlua::Value::Nil,
-				mlua::Value::Nil,
-				mlua::Value::Nil,
-				mlua::Value::Nil,
-				mlua::Value::Nil,
-			]=>Ok(Self{hits,details:None}),
-			&mut [
-				mlua::Value::Boolean(hits),
-				mlua::Value::Number(distance),
-				mlua::Value::Vector(p_pos),
-				mlua::Value::Vector(p_norm),
-				mlua::Value::Vector(q_pos),
-				mlua::Value::Vector(q_norm),
-			]=>Ok(Self{
-				hits,
-				details:Some(Details{
-					distance:distance.try_into().unwrap(),
-					p_pos:p64v3(p_pos).unwrap(),
-					p_norm:p64v3(p_norm).unwrap(),
-					q_pos:p64v3(q_pos).unwrap(),
-					q_norm:p64v3(q_norm).unwrap(),
-				}),
-			}),
-			&mut [
-				mlua::Value::Boolean(hits),
-				mlua::Value::Integer(distance),
-				mlua::Value::Vector(p_pos),
-				mlua::Value::Vector(p_norm),
-				mlua::Value::Vector(q_pos),
-				mlua::Value::Vector(q_norm),
-			]=>Ok(Self{
-				hits,
-				details:Some(Details{
-					distance:distance.into(),
-					p_pos:p64v3(p_pos).unwrap(),
-					p_norm:p64v3(p_norm).unwrap(),
-					q_pos:p64v3(q_pos).unwrap(),
-					q_norm:p64v3(q_norm).unwrap(),
-				}),
-			}),
-			values=>Err(mlua::Error::runtime(format!("Invalid return values: {values:?}"))),
-		}
-	}
-}
-
-struct Args{
-	query_p:Function,
-	radius_p:f64,
-	query_q:Function,
-	radius_q:f64,
-	test_intersection:bool,
-}
-impl Args{
-	fn new(
-		lua:&Lua,
-		mesh:&'static MinkowskiMesh<'static>,
-		point:Planar64Vec3,
-		test_intersection:bool,
-	)->LuaResult<Self>{
-		let radius_p=0.0;
-		let radius_q=0.0;
-		// Query the farthest point on the mesh in the given direction.
-		let query_p=lua.create_function(move|_,dir:Option<Vector>|{
-			let Some(dir)=dir else{
-				return Ok(vec(mesh.mesh0.hint_point()));
-			};
-			let dir=p64v3(dir).unwrap();
-			let vert_id=mesh.mesh0.farthest_vert(dir);
-			let dir=mesh.mesh0.vert(vert_id);
-			Ok(vec(dir))
-		})?;
-		// query_q is different since it includes the test point offset.
-		let query_q=lua.create_function(move|_,dir:Option<Vector>|{
-			let Some(dir)=dir else{
-				return Ok(vec(mesh.mesh1.hint_point()+point));
-			};
-			let dir=p64v3(dir).unwrap();
-			let vert_id=mesh.mesh1.farthest_vert(dir);
-			let dir=mesh.mesh1.vert(vert_id)+point;
-			Ok(vec(dir))
-		})?;
-		Ok(Args{
-			query_p,
-			radius_p,
-			query_q,
-			radius_q,
-			test_intersection,
-		})
-	}
-}
-impl IntoLuaMulti for Args{
-	fn into_lua_multi(self,lua:&Lua)->LuaResult<mlua::MultiValue>{
-		use mlua::IntoLua;
-		Ok(mlua::MultiValue::from_vec(vec![
-			self.query_p.into_lua(lua)?,
-			self.radius_p.into_lua(lua)?,
-			self.query_q.into_lua(lua)?,
-			self.radius_q.into_lua(lua)?,
-			mlua::Value::Nil,
-			self.test_intersection.into_lua(lua)?,
-		]))
-	}
-}
-
-fn minimum_difference(
-	mesh:&MinkowskiMesh,
-	point:Planar64Vec3,
-	test_intersection:bool,
-)->LuaResult<MinimumDifference>{
-	let ctx=init_lua()?;
-	// SAFETY: mesh lifetime must outlive args usages
-	let mesh=unsafe{core::mem::transmute(mesh)};
-	let args=Args::new(&ctx.lua,mesh,point,test_intersection)?;
-	ctx.f.call(args)
-}
-
-struct Ctx{
-	lua:Lua,
-	f:Function,
-}
-fn init_lua()->LuaResult<Ctx>{
-	static SOURCE:std::sync::LazyLock<String>=std::sync::LazyLock::new(||std::fs::read_to_string("Trey-MinimumDifference.lua").unwrap());
-	let lua=Lua::new();
-	lua.sandbox(true)?;
-	let lib_f=lua.load(SOURCE.as_str()).set_name("Trey-MinimumDifference").into_function()?;
-	let lib:mlua::Table=lib_f.call(())?;
-	let f=lib.raw_get("difference")?;
-	Ok(Ctx{lua,f})
-}
--- a/engine/physics/src/model.rs
+++ b/engine/physics/src/model.rs
@@ -5,7 +5,7 @@ use strafesnet_common::model::{self,MeshId,PolygonIter};
 use strafesnet_common::integer::{self,vec3,Fixed,Planar64,Planar64Vec3,Ratio};
 use strafesnet_common::physics::Time;

-type Body=crate::body::Body<strafesnet_common::physics::TimeInner>;
+type Trajectory<'a>=crate::body::Trajectory<'a,strafesnet_common::physics::TimeInner>;

 struct AsRefHelper<T>(T);
 impl<T> AsRef<T> for AsRefHelper<T>{
@@ -16,14 +16,14 @@ impl<T> AsRef<T> for AsRefHelper<T>{

 pub trait UndirectedEdge{
 	type DirectedEdge:Copy+DirectedEdge;
-	fn as_directed(&self,parity:bool)->Self::DirectedEdge;
+	fn as_directed(self,parity:bool)->Self::DirectedEdge;
 }
-pub trait DirectedEdge{
+pub trait DirectedEdge:Copy{
 	type UndirectedEdge:Copy+std::fmt::Debug+UndirectedEdge;
-	fn as_undirected(&self)->Self::UndirectedEdge;
+	fn as_undirected(self)->Self::UndirectedEdge;
 	fn parity(&self)->bool;
 	//this is stupid but may work fine
-	fn reverse(&self)-><<Self as DirectedEdge>::UndirectedEdge as UndirectedEdge>::DirectedEdge{
+	fn reverse(self)-><<Self as DirectedEdge>::UndirectedEdge as UndirectedEdge>::DirectedEdge{
 		self.as_undirected().as_directed(!self.parity())
 	}
 }
@@ -45,13 +45,13 @@ pub struct SubmeshFaceId(u32);

 impl UndirectedEdge for SubmeshEdgeId{
 	type DirectedEdge=SubmeshDirectedEdgeId;
-	fn as_directed(&self,parity:bool)->SubmeshDirectedEdgeId{
+	fn as_directed(self,parity:bool)->SubmeshDirectedEdgeId{
 		SubmeshDirectedEdgeId(self.0|((parity as u32)<<(u32::BITS-1)))
 	}
 }
 impl DirectedEdge for SubmeshDirectedEdgeId{
 	type UndirectedEdge=SubmeshEdgeId;
-	fn as_undirected(&self)->SubmeshEdgeId{
+	fn as_undirected(self)->SubmeshEdgeId{
 		SubmeshEdgeId(self.0&!(1<<(u32::BITS-1)))
 	}
 	fn parity(&self)->bool{
@@ -597,7 +597,7 @@ impl core::ops::Neg for MinkowskiVert{
 		}
 	}
 }
-#[derive(Clone,Copy,Debug,Eq,PartialEq)]
+#[derive(Clone,Copy,Debug)]
 pub enum MinkowskiEdge{
 	VertEdge(SubmeshVertId,SubmeshEdgeId),
 	EdgeVert(SubmeshEdgeId,SubmeshVertId),
@@ -605,14 +605,14 @@ pub enum MinkowskiEdge{
 }
 impl UndirectedEdge for MinkowskiEdge{
 	type DirectedEdge=MinkowskiDirectedEdge;
-	fn as_directed(&self,parity:bool)->Self::DirectedEdge{
+	fn as_directed(self,parity:bool)->Self::DirectedEdge{
 		match self{
-			MinkowskiEdge::VertEdge(v0,e1)=>MinkowskiDirectedEdge::VertEdge(*v0,e1.as_directed(parity)),
-			MinkowskiEdge::EdgeVert(e0,v1)=>MinkowskiDirectedEdge::EdgeVert(e0.as_directed(parity),*v1),
+			MinkowskiEdge::VertEdge(v0,e1)=>MinkowskiDirectedEdge::VertEdge(v0,e1.as_directed(parity)),
+			MinkowskiEdge::EdgeVert(e0,v1)=>MinkowskiDirectedEdge::EdgeVert(e0.as_directed(parity),v1),
 		}
 	}
 }
-#[derive(Clone,Copy,Debug,Eq,PartialEq)]
+#[derive(Clone,Copy,Debug)]
 pub enum MinkowskiDirectedEdge{
 	VertEdge(SubmeshVertId,SubmeshDirectedEdgeId),
 	EdgeVert(SubmeshDirectedEdgeId,SubmeshVertId),
@@ -620,10 +620,10 @@ pub enum MinkowskiDirectedEdge{
 }
 impl DirectedEdge for MinkowskiDirectedEdge{
 	type UndirectedEdge=MinkowskiEdge;
-	fn as_undirected(&self)->Self::UndirectedEdge{
+	fn as_undirected(self)->Self::UndirectedEdge{
 		match self{
-			MinkowskiDirectedEdge::VertEdge(v0,e1)=>MinkowskiEdge::VertEdge(*v0,e1.as_undirected()),
-			MinkowskiDirectedEdge::EdgeVert(e0,v1)=>MinkowskiEdge::EdgeVert(e0.as_undirected(),*v1),
+			MinkowskiDirectedEdge::VertEdge(v0,e1)=>MinkowskiEdge::VertEdge(v0,e1.as_undirected()),
+			MinkowskiDirectedEdge::EdgeVert(e0,v1)=>MinkowskiEdge::EdgeVert(e0.as_undirected(),v1),
 		}
 	}
 	fn parity(&self)->bool{
@@ -645,8 +645,8 @@ pub enum MinkowskiFace{

 #[derive(Debug)]
 pub struct MinkowskiMesh<'a>{
-	pub mesh0:TransformedMesh<'a>,
-	pub mesh1:TransformedMesh<'a>,
+	mesh0:TransformedMesh<'a>,
+	mesh1:TransformedMesh<'a>,
 }

 pub type GigaTime=Ratio<Fixed<4,128>,Fixed<4,128>>;
@@ -670,39 +670,40 @@ impl MinkowskiMesh<'_>{
 			mesh1,
 		}
 	}
-	pub fn predict_collision_in(&self,relative_body:&Body,range:impl RangeBounds<Time>)->Result<Option<(MinkowskiFace,GigaTime)>,crate::minimum_difference::InfiniteLoop>{
-		let Some(fev)=crate::minimum_difference::closest_fev_not_inside(self,relative_body.position)?else{
-			return Ok(None);
+	pub fn predict_collision_in(&self,trajectory:&Trajectory,range:impl RangeBounds<Time>)->Option<(MinkowskiFace,GigaTime)>{
+		let start_position=match range.start_bound(){
+			Bound::Included(time)=>trajectory.extrapolated_position(*time),
+			Bound::Excluded(time)=>trajectory.extrapolated_position(*time),
+			Bound::Unbounded=>trajectory.position,
 		};
+		let fev=crate::minimum_difference::closest_fev_not_inside(self,start_position)?;
 		//continue forwards along the body parabola
-		Ok(fev.crawl(self,relative_body,range.start_bound(),range.end_bound()).hit())
+		fev.crawl(self,trajectory,range.start_bound(),range.end_bound()).hit()
 	}
-	pub fn predict_collision_out(&self,relative_body:&Body,range:impl RangeBounds<Time>)->Result<Option<(MinkowskiFace,GigaTime)>,crate::minimum_difference::InfiniteLoop>{
+	pub fn predict_collision_out(&self,trajectory:&Trajectory,range:impl RangeBounds<Time>)->Option<(MinkowskiFace,GigaTime)>{
 		let (lower_bound,upper_bound)=(range.start_bound(),range.end_bound());
 		// TODO: handle unbounded collision using infinity fev
-		let time=match upper_bound{
-			Bound::Included(&time)=>time,
-			Bound::Excluded(&time)=>time,
-			Bound::Unbounded=>unimplemented!("unbounded collision out"),
-		};
-		let Some(fev)=crate::minimum_difference::closest_fev_not_inside(self,relative_body.extrapolated_position(time))?else{
-			return Ok(None);
+		let start_position=match upper_bound{
+			Bound::Included(time)=>trajectory.extrapolated_position(*time),
+			Bound::Excluded(time)=>trajectory.extrapolated_position(*time),
+			Bound::Unbounded=>trajectory.position,
 		};
+		let fev=crate::minimum_difference::closest_fev_not_inside(self,start_position)?;
 		// swap and negate bounds to do a time inversion
 		let (lower_bound,upper_bound)=(upper_bound.map(|&t|-t),lower_bound.map(|&t|-t));
-		let infinity_body=-relative_body;
+		let time_reversed_trajectory=-trajectory;
 		//continue backwards along the body parabola
-		Ok(fev.crawl(self,&infinity_body,lower_bound.as_ref(),upper_bound.as_ref()).hit()
+		fev.crawl(self,&time_reversed_trajectory,lower_bound.as_ref(),upper_bound.as_ref()).hit()
 			//no need to test -time<time_limit because of the first step
-			.map(|(face,time)|(face,-time)))
+			.map(|(face,time)|(face,-time))
 	}
-	pub fn predict_collision_face_out(&self,relative_body:&Body,range:impl RangeBounds<Time>,contact_face_id:MinkowskiFace)->Option<(MinkowskiDirectedEdge,GigaTime)>{
+	pub fn predict_collision_face_out(&self,trajectory:&Trajectory,range:impl RangeBounds<Time>,contact_face_id:MinkowskiFace)->Option<(MinkowskiDirectedEdge,GigaTime)>{
 		// TODO: make better
 		use crate::face_crawler::{low,upp};
 		//no algorithm needed, there is only one state and two cases (Edge,None)
 		//determine when it passes an edge ("sliding off" case)
-		let start_time=range.start_bound().map(|&t|(t-relative_body.time).to_ratio());
-		let mut best_time=range.end_bound().map(|&t|into_giga_time(t,relative_body.time));
+		let start_time=range.start_bound().map(|&t|(t-trajectory.time).to_ratio());
+		let mut best_time=range.end_bound().map(|&t|into_giga_time(t,trajectory.time));
 		let mut best_edge=None;
 		let face_n=self.face_nd(contact_face_id).0;
 		for &directed_edge_id in self.face_edges(contact_face_id).as_ref(){
@@ -714,8 +715,8 @@ impl MinkowskiMesh<'_>{
 			//WARNING! d outside of *2
 			//WARNING: truncated precision
 			//wrap for speed
-			for dt in Fixed::<4,128>::zeroes2(((n.dot(relative_body.position))*2-d).wrap_4(),n.dot(relative_body.velocity).wrap_4()*2,n.dot(relative_body.acceleration).wrap_4()){
-				if low(&start_time,&dt)&&upp(&dt,&best_time)&&n.dot(relative_body.extrapolated_velocity_ratio_dt(dt)).is_negative(){
+			for dt in Fixed::<4,128>::zeroes2(((n.dot(trajectory.position))*2-d).wrap_4(),n.dot(trajectory.velocity).wrap_4()*2,n.dot(trajectory.acceleration).wrap_4()){
+				if low(&start_time,&dt)&&upp(&dt,&best_time)&&n.dot(trajectory.extrapolated_velocity_ratio_dt(dt)).is_negative(){
 					best_time=Bound::Included(dt);
 					best_edge=Some((directed_edge_id,dt));
 					break;
--- a/engine/physics/src/physics.rs
+++ b/engine/physics/src/physics.rs
@@ -15,6 +15,7 @@ pub use strafesnet_common::physics::{Time,TimeInner};
 use gameplay::ModeState;

 pub type Body=crate::body::Body<TimeInner>;
+pub type Trajectory<'a>=crate::body::Trajectory<'a,TimeInner>;
 type MouseState=strafesnet_common::mouse::MouseState<TimeInner>;

 //external influence
@@ -28,6 +29,7 @@ pub enum InternalInstruction{
 	CollisionStart(Collision,model_physics::GigaTime),
 	CollisionEnd(Collision,model_physics::GigaTime),
 	StrafeTick,
+	// TODO: add GigaTime to ReachWalkTargetVelocity
 	ReachWalkTargetVelocity,
 	// Water,
 }
@@ -498,16 +500,20 @@ enum MoveState{
 }
 impl MoveState{
 	//call this after state.move_state is changed
-	fn apply_enum(&self,body:&mut Body,touching:&TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,style:&StyleModifiers,camera:&PhysicsCamera,input_state:&InputState){
+	fn acceleration(&self,touching:&TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,style:&StyleModifiers,camera:&PhysicsCamera,input_state:&InputState)->Planar64Vec3{
 		match self{
-			MoveState::Fly=>body.acceleration=vec3::zero(),
-			MoveState::Air=>{
-				//calculate base acceleration
-				let a=touching.base_acceleration(models,style,camera,input_state);
-				//set_acceleration clips according to contacts
-				set_acceleration(body,touching,models,hitbox_mesh,a);
+			MoveState::Fly=>vec3::zero(),
+			MoveState::Air
+			|MoveState::Water
+			=>{
+				// calculate base acceleration
+				let base_acceleration=touching.base_acceleration(models,style,camera,input_state);
+				// constrain_acceleration clips according to contacts
+				touching.constrain_acceleration(models,hitbox_mesh,base_acceleration)
 			},
-			_=>(),
+			MoveState::Walk(walk_state)
+			|MoveState::Ladder(walk_state)
+			=>walk_state.target.acceleration(),
 		}
 	}
 	//function to coerce &mut self into &self
@@ -521,13 +527,9 @@ impl MoveState{
 				//set_velocity clips velocity according to current touching state
 				set_velocity(body,touching,models,hitbox_mesh,v);
 			},
-			MoveState::Walk(walk_state)
-			|MoveState::Ladder(walk_state)
-			=>{
-				//accelerate towards walk target or do nothing
-				let a=walk_state.target.acceleration();
-				set_acceleration(body,touching,models,hitbox_mesh,a);
-			},
+			MoveState::Walk(_walk_state)
+			|MoveState::Ladder(_walk_state)
+			=>(),
 		}
 	}
 	/// changes the move state
@@ -590,12 +592,10 @@ impl MoveState{
 	}
 	//lmao idk this is convenient
 	fn apply_enum_and_input_and_body(&mut self,body:&mut Body,touching:&TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,style:&StyleModifiers,camera:&PhysicsCamera,input_state:&InputState){
-		self.apply_enum(body,touching,models,hitbox_mesh,style,camera,input_state);
 		self.apply_input(body,touching,models,hitbox_mesh,style,camera,input_state);
 		self.apply_to_body(body,touching,models,hitbox_mesh,style,camera,input_state);
 	}
 	fn apply_enum_and_body(&mut self,body:&mut Body,touching:&TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,style:&StyleModifiers,camera:&PhysicsCamera,input_state:&InputState){
-		self.apply_enum(body,touching,models,hitbox_mesh,style,camera,input_state);
 		self.apply_to_body(body,touching,models,hitbox_mesh,style,camera,input_state);
 	}
 	fn apply_input_and_body(&mut self,body:&mut Body,touching:&TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,style:&StyleModifiers,camera:&PhysicsCamera,input_state:&InputState){
@@ -815,7 +815,7 @@ impl TouchingState{
 				normal:n,
 			}
 		}).collect();
-		crate::push_solve::push_solve(&contacts,velocity)
+		crate::push_solve::push_solve(&contacts,velocity).0
 	}
 	fn constrain_acceleration(&self,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,acceleration:Planar64Vec3)->Planar64Vec3{
 		let contacts:Vec<_>=self.contacts.iter().map(|(convex_mesh_id,face_id)|{
@@ -826,18 +826,17 @@ impl TouchingState{
 				normal:n,
 			}
 		}).collect();
-		crate::push_solve::push_solve(&contacts,acceleration)
+		crate::push_solve::push_solve(&contacts,acceleration).0
 	}
-	fn predict_collision_end(&self,collector:&mut instruction::InstructionCollector<InternalInstruction,Time>,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,body:&Body,start_time:Time)->Result<(),crate::minimum_difference::InfiniteLoop>{
+	fn predict_collision_end(&self,collector:&mut instruction::InstructionCollector<InternalInstruction,Time>,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,trajectory:&Trajectory,start_time:Time){
 		// let relative_body=body.relative_to(&Body::ZERO);
-		let relative_body=body;
 		for (convex_mesh_id,face_id) in &self.contacts{
 			//detect face slide off
 			let model_mesh=models.contact_mesh(convex_mesh_id);
 			let minkowski=model_physics::MinkowskiMesh::minkowski_sum(model_mesh,hitbox_mesh.transformed_mesh());
-			collector.collect(minkowski.predict_collision_face_out(&relative_body,start_time..collector.time(),*face_id).map(|(_face,time)|{
+			collector.collect(minkowski.predict_collision_face_out(&trajectory,start_time..collector.time(),*face_id).map(|(_face,time)|{
 				TimedInstruction{
-					time:relative_body.time+time.into(),
+					time:trajectory.time+time.into(),
 					instruction:InternalInstruction::CollisionEnd(
 						Collision::Contact(ContactCollision{face_id:*face_id,convex_mesh_id:*convex_mesh_id}),
 						time
@@ -849,9 +848,9 @@ impl TouchingState{
 			//detect model collision in reverse
 			let model_mesh=models.intersect_mesh(convex_mesh_id);
 			let minkowski=model_physics::MinkowskiMesh::minkowski_sum(model_mesh,hitbox_mesh.transformed_mesh());
-			collector.collect(minkowski.predict_collision_out(&relative_body,start_time..collector.time())?.map(|(_face,time)|{
+			collector.collect(minkowski.predict_collision_out(&trajectory,start_time..collector.time()).map(|(_face,time)|{
 				TimedInstruction{
-					time:relative_body.time+time.into(),
+					time:trajectory.time+time.into(),
 					instruction:InternalInstruction::CollisionEnd(
 						Collision::Intersect(IntersectCollision{convex_mesh_id:*convex_mesh_id}),
 						time
@@ -859,7 +858,6 @@ impl TouchingState{
 				}
 			}));
 		}
-		Ok(())
 	}
 }

@@ -887,7 +885,7 @@ pub struct PhysicsState{
 impl Default for PhysicsState{
 	fn default()->Self{
 		Self{
-			body:Body::new(vec3::int(0,50,0),vec3::int(0,0,0),vec3::int(0,-100,0),Time::ZERO),
+			body:Body::new(vec3::int(0,50,0),vec3::int(0,0,0),Time::ZERO),
 			time:Time::ZERO,
 			style:StyleModifiers::default(),
 			touching:TouchingState::default(),
@@ -911,11 +909,14 @@ impl PhysicsState{
 	pub const fn body(&self)->&Body{
 		&self.body
 	}
-	pub fn camera_body(&self)->Body{
-		Body{
-			position:self.body.position+self.style.camera_offset,
-			..self.body
-		}
+	pub fn camera_trajectory(&self,data:&PhysicsData)->Trajectory<'static>{
+		let acceleration=self.acceleration(data);
+		Trajectory::new(
+			self.body.position+self.style.camera_offset,
+			self.body.velocity,
+			acceleration,
+			self.body.time,
+		)
 	}
 	pub const fn camera(&self)->PhysicsCamera{
 		self.camera
@@ -947,6 +948,9 @@ impl PhysicsState{
 	fn apply_input_and_body(&mut self,data:&PhysicsData){
 		self.move_state.apply_input_and_body(&mut self.body,&self.touching,&data.models,&data.hitbox_mesh,&self.style,&self.camera,&self.input_state);
 	}
+	fn acceleration(&self,data:&PhysicsData)->Planar64Vec3{
+		self.move_state.acceleration(&self.touching,&data.models,&data.hitbox_mesh,&self.style,&self.camera,&self.input_state)
+	}
 	//state mutated on collision:
 	//Accelerator
 	//stair step-up
@@ -1199,15 +1203,15 @@ impl<'a> PhysicsContext<'a>{

 		collector.collect(state.next_move_instruction());

+		let trajectory=state.body.with_acceleration(state.acceleration(data));
 		//check for collision ends
-		state.touching.predict_collision_end(&mut collector,&data.models,&data.hitbox_mesh,&state.body,state.time).unwrap();
+		state.touching.predict_collision_end(&mut collector,&data.models,&data.hitbox_mesh,&trajectory,state.time);
 		//check for collision starts
 		let mut aabb=aabb::Aabb::default();
-		state.body.grow_aabb(&mut aabb,state.time,collector.time());
+		trajectory.grow_aabb(&mut aabb,state.time,collector.time());
 		aabb.inflate(data.hitbox_mesh.halfsize);
 		//relative to moving platforms
 		//let relative_body=state.body.relative_to(&Body::ZERO);
-		let relative_body=&state.body;
 		data.bvh.sample_aabb(&aabb,&mut |convex_mesh_id|{
 			if state.touching.contains(convex_mesh_id){
 				return;
@@ -1215,17 +1219,17 @@ impl<'a> PhysicsContext<'a>{
 			//no checks are needed because of the time limits.
 			let model_mesh=data.models.mesh(*convex_mesh_id);
 			let minkowski=model_physics::MinkowskiMesh::minkowski_sum(model_mesh,data.hitbox_mesh.transformed_mesh());
-			let Ok(collision)=minkowski.predict_collision_in(relative_body,state.time..collector.time())else{
-				println!("Infinite loop! body={relative_body}");
-				return;
-			};
-			collector.collect(collision.map(|(face,dt)|TimedInstruction{
-				time:relative_body.time+dt.into(),
-				instruction:InternalInstruction::CollisionStart(
-					Collision::new(*convex_mesh_id,face),
-					dt
+			collector.collect(minkowski.predict_collision_in(&trajectory,state.time..collector.time())
+				.map(|(face,dt)|
+					TimedInstruction{
+						time:trajectory.time+dt.into(),
+						instruction:InternalInstruction::CollisionStart(
+							Collision::new(*convex_mesh_id,face),
+							dt
+						)
+					}
 				)
-			}));
+			);
 		});
 		collector.take()
 	}
@@ -1336,24 +1340,6 @@ fn set_velocity_cull(body:&mut Body,touching:&mut TouchingState,models:&PhysicsM
 fn set_velocity(body:&mut Body,touching:&TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,v:Planar64Vec3){
 	body.velocity=touching.constrain_velocity(models,hitbox_mesh,v);
 }
-#[expect(dead_code)]
-fn set_acceleration_cull(body:&mut Body,touching:&mut TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,a:Planar64Vec3)->bool{
-	//This is not correct but is better than what I have
-	let mut culled=false;
-	touching.contacts.retain(|convex_mesh_id,face_id|{
-		let n=contact_normal(models,hitbox_mesh,convex_mesh_id,*face_id);
-		let r=n.dot(a).is_positive();
-		if r{
-			culled=true;
-		}
-		!r
-	});
-	set_acceleration(body,touching,models,hitbox_mesh,a);
-	culled
-}
-fn set_acceleration(body:&mut Body,touching:&TouchingState,models:&PhysicsModels,hitbox_mesh:&HitboxMesh,a:Planar64Vec3){
-	body.acceleration=touching.constrain_acceleration(models,hitbox_mesh,a);
-}

 fn teleport(
 	point:Planar64Vec3,
@@ -1372,7 +1358,6 @@ fn teleport(
 	time:Time,
 ){
 	set_position(point,move_state,body,touching,run,mode_state,mode,models,hitbox_mesh,bvh,style,camera,input_state,time);
-	set_acceleration(body,touching,models,hitbox_mesh,style.gravity);
 }
 enum TeleportToSpawnError{
 	NoModel,
@@ -1670,7 +1655,20 @@ fn collision_start_intersect(
 			},
 			Some(gameplay_modes::Zone::Finish)=>{
 				match run.finish(time){
-					Ok(())=>println!("@@@@ Finished run time={}",run.time(time)),
+					Ok(())=>{
+						let time=run.time(time);
+						let h=time.get()/(Time::ONE_SECOND.get()*60*60);
+						let m=(time.get()/(Time::ONE_SECOND.get()*60)).rem_euclid(60);
+						let s=(time.get()/(Time::ONE_SECOND.get())).rem_euclid(60);
+						let ms=(time.get()/(Time::ONE_MILLISECOND.get())).rem_euclid(1000);
+						let us=(time.get()/(Time::ONE_MICROSECOND.get())).rem_euclid(1000);
+						let ns=(time.get()/(Time::ONE_NANOSECOND.get())).rem_euclid(1000);
+						if h==0{
+							println!("@@@@ Finished run time={m:02}:{s:02}.{ms:03}_{us:03}_{ns:03}");
+						}else{
+							println!("@@@@ Finished run time={h}:{m:02}:{s:02}.{ms:03}_{us:03}_{ns:03}");
+						}
+					},
 					Err(e)=>println!("@@@@ Run Finish error:{e:?}"),
 				}
 			},
@@ -1744,99 +1742,99 @@ fn collision_end_intersect(
 }
 fn atomic_internal_instruction(state:&mut PhysicsState,data:&PhysicsData,ins:TimedInstruction<InternalInstruction,Time>){
 	state.time=ins.time;
-	let (should_advance_body,goober_time)=match ins.instruction{
+	match ins.instruction{
+		// collisions advance the body precisely
 		InternalInstruction::CollisionStart(_,dt)
-		|InternalInstruction::CollisionEnd(_,dt)=>(true,Some(dt)),
-		InternalInstruction::StrafeTick
-		|InternalInstruction::ReachWalkTargetVelocity=>(true,None),
-	};
-	if should_advance_body{
-		match goober_time{
-			Some(dt)=>state.body.advance_time_ratio_dt(dt),
-			None=>state.body.advance_time(state.time),
-		}
+		|InternalInstruction::CollisionEnd(_,dt)=>{
+			state.body=state.body.with_acceleration(state.acceleration(data)).extrapolated_body_ratio_dt(dt);
+		},
+		// this advances imprecisely
+		InternalInstruction::ReachWalkTargetVelocity=>state.body=state.body.with_acceleration(state.acceleration(data)).extrapolated_body(state.time),
+		// strafe tick decides for itself whether to advance the body.
+		InternalInstruction::StrafeTick=>(),
 	}
-		match ins.instruction{
-			InternalInstruction::CollisionStart(collision,_)=>{
-				let mode=data.modes.get_mode(state.mode_state.get_mode_id());
-				match collision{
-					Collision::Contact(contact)=>collision_start_contact(
-						&mut state.move_state,&mut state.body,&mut state.mode_state,&mut state.touching,&mut state.run,
-						mode,
-						&data.models,&data.hitbox_mesh,&data.bvh,&state.style,&state.camera,&state.input_state,
-						data.models.contact_attr(contact.convex_mesh_id.model_id),
-						contact,
-						state.time,
-					),
-					Collision::Intersect(intersect)=>collision_start_intersect(
-						&mut state.move_state,&mut state.body,&mut state.mode_state,&mut state.touching,
-						mode,
-						&mut state.run,&data.models,&data.hitbox_mesh,&data.bvh,&state.style,&state.camera,&state.input_state,
-						data.models.intersect_attr(intersect.convex_mesh_id.model_id),
-						intersect,
-						state.time,
-					),
-				}
-			},
-			InternalInstruction::CollisionEnd(collision,_)=>match collision{
-				Collision::Contact(contact)=>collision_end_contact(
-					&mut state.move_state,&mut state.body,&mut state.touching,&data.models,&data.hitbox_mesh,&state.style,&state.camera,&state.input_state,
+	match ins.instruction{
+		InternalInstruction::CollisionStart(collision,_)=>{
+			let mode=data.modes.get_mode(state.mode_state.get_mode_id());
+			match collision{
+				Collision::Contact(contact)=>collision_start_contact(
+					&mut state.move_state,&mut state.body,&mut state.mode_state,&mut state.touching,&mut state.run,
+					mode,
+					&data.models,&data.hitbox_mesh,&data.bvh,&state.style,&state.camera,&state.input_state,
 					data.models.contact_attr(contact.convex_mesh_id.model_id),
-					&contact.convex_mesh_id
+					contact,
+					state.time,
 				),
-				Collision::Intersect(intersect)=>collision_end_intersect(
-					&mut state.move_state,&mut state.body,&mut state.touching,&data.models,&data.hitbox_mesh,&state.style,&state.camera,&state.input_state,
-					data.modes.get_mode(state.mode_state.get_mode_id()),
-					&mut state.run,
+				Collision::Intersect(intersect)=>collision_start_intersect(
+					&mut state.move_state,&mut state.body,&mut state.mode_state,&mut state.touching,
+					mode,
+					&mut state.run,&data.models,&data.hitbox_mesh,&data.bvh,&state.style,&state.camera,&state.input_state,
 					data.models.intersect_attr(intersect.convex_mesh_id.model_id),
-					&intersect.convex_mesh_id,
-					state.time
+					intersect,
+					state.time,
 				),
-			},
-			InternalInstruction::StrafeTick=>{
-				//TODO make this less huge
-				if let Some(strafe_settings)=&state.style.strafe{
-					let controls=state.input_state.controls;
-					if strafe_settings.activates(controls){
-						let masked_controls=strafe_settings.mask(controls);
-						let control_dir=state.style.get_control_dir(masked_controls);
-						if control_dir!=vec3::zero(){
-							let camera_mat=state.camera.simulate_move_rotation_y(state.input_state.lerp_delta(state.time).x);
-							if let Some(ticked_velocity)=strafe_settings.tick_velocity(state.body.velocity,(camera_mat*control_dir).with_length(Planar64::ONE).divide().wrap_1()){
-								//this is wrong but will work ig
-								//need to note which push planes activate in push solve and keep those
-								state.cull_velocity(data,ticked_velocity);
-							}
+			}
+		},
+		InternalInstruction::CollisionEnd(collision,_)=>match collision{
+			Collision::Contact(contact)=>collision_end_contact(
+				&mut state.move_state,&mut state.body,&mut state.touching,&data.models,&data.hitbox_mesh,&state.style,&state.camera,&state.input_state,
+				data.models.contact_attr(contact.convex_mesh_id.model_id),
+				&contact.convex_mesh_id
+			),
+			Collision::Intersect(intersect)=>collision_end_intersect(
+				&mut state.move_state,&mut state.body,&mut state.touching,&data.models,&data.hitbox_mesh,&state.style,&state.camera,&state.input_state,
+				data.modes.get_mode(state.mode_state.get_mode_id()),
+				&mut state.run,
+				data.models.intersect_attr(intersect.convex_mesh_id.model_id),
+				&intersect.convex_mesh_id,
+				state.time
+			),
+		},
+		InternalInstruction::StrafeTick=>{
+			//TODO make this less huge
+			if let Some(strafe_settings)=&state.style.strafe{
+				let controls=state.input_state.controls;
+				if strafe_settings.activates(controls){
+					let masked_controls=strafe_settings.mask(controls);
+					let control_dir=state.style.get_control_dir(masked_controls);
+					if control_dir!=vec3::zero(){
+						// manually advance time
+						state.body=state.body.with_acceleration(state.acceleration(data)).extrapolated_body(state.time);
+						let camera_mat=state.camera.simulate_move_rotation_y(state.input_state.lerp_delta(state.time).x);
+						if let Some(ticked_velocity)=strafe_settings.tick_velocity(state.body.velocity,(camera_mat*control_dir).with_length(Planar64::ONE).divide().wrap_1()){
+							//this is wrong but will work ig
+							//need to note which push planes activate in push solve and keep those
+							state.cull_velocity(data,ticked_velocity);
 						}
 					}
 				}
 			}
-			InternalInstruction::ReachWalkTargetVelocity=>{
-				match &mut state.move_state{
-					MoveState::Air
-					|MoveState::Water
-					|MoveState::Fly
-					=>println!("ReachWalkTargetVelocity fired for non-walking MoveState"),
-					MoveState::Walk(walk_state)|MoveState::Ladder(walk_state)=>{
-						//velocity is already handled by advance_time
-						//we know that the acceleration is precisely zero because the walk target is known to be reachable
-						//which means that gravity can be fully cancelled
-						//ignore moving platforms for now
-						let target=core::mem::replace(&mut walk_state.target,TransientAcceleration::Reached);
-						set_acceleration(&mut state.body,&state.touching,&data.models,&data.hitbox_mesh,vec3::zero());
-						// check what the target was to see if it was invalid
-						match target{
-							//you are not supposed to reach a walk target which is already reached!
-							TransientAcceleration::Reached=>println!("Invalid walk target: Reached"),
-							TransientAcceleration::Reachable{..}=>(),
-							//you are not supposed to reach an unreachable walk target!
-							TransientAcceleration::Unreachable{..}=>println!("Invalid walk target: Unreachable"),
-						}
+		}
+		InternalInstruction::ReachWalkTargetVelocity=>{
+			match &mut state.move_state{
+				MoveState::Air
+				|MoveState::Water
+				|MoveState::Fly
+				=>println!("ReachWalkTargetVelocity fired for non-walking MoveState"),
+				MoveState::Walk(walk_state)|MoveState::Ladder(walk_state)=>{
+					//velocity is already handled by extrapolated_body
+					//we know that the acceleration is precisely zero because the walk target is known to be reachable
+					//which means that gravity can be fully cancelled
+					//ignore moving platforms for now
+					let target=core::mem::replace(&mut walk_state.target,TransientAcceleration::Reached);
+					// check what the target was to see if it was invalid
+					match target{
+						//you are not supposed to reach a walk target which is already reached!
+						TransientAcceleration::Reached=>println!("Invalid walk target: Reached"),
+						TransientAcceleration::Reachable{..}=>(),
+						//you are not supposed to reach an unreachable walk target!
+						TransientAcceleration::Unreachable{..}=>println!("Invalid walk target: Unreachable"),
 					}
 				}
-			},
-		}
+			}
+		},
 	}
+}

 fn atomic_input_instruction(state:&mut PhysicsState,data:&PhysicsData,ins:TimedInstruction<Instruction,Time>){
 	state.time=ins.time;
@@ -1862,7 +1860,7 @@ fn atomic_input_instruction(state:&mut PhysicsState,data:&PhysicsData,ins:TimedI
 		Instruction::Misc(MiscInstruction::PracticeFly)=>true,
 	};
 	if should_advance_body{
-		state.body.advance_time(state.time);
+		state.body=state.body.with_acceleration(state.acceleration(data)).extrapolated_body(state.time);
 	}

 	let mut b_refresh_walk_target=true;
@@ -1898,6 +1896,9 @@ fn atomic_input_instruction(state:&mut PhysicsState,data:&PhysicsData,ins:TimedI
 			state.input_state.set_control(Controls::Zoom,s);
 			b_refresh_walk_target=false;
 		},
+		Instruction::SetControl(SetControlInstruction::SetSprint(s))=>{
+			state.input_state.set_control(Controls::Sprint,s);
+		},
 		Instruction::Mode(ModeInstruction::Reset)=>{
 			//totally reset physics state
 			state.reset_to_default();
@@ -1967,16 +1968,16 @@ fn atomic_input_instruction(state:&mut PhysicsState,data:&PhysicsData,ins:TimedI
 mod test{
 	use strafesnet_common::integer::{vec3::{self,int as int3},mat3};
 	use super::*;
-	fn test_collision_axis_aligned(relative_body:Body,expected_collision_time:Option<Time>){
+	fn test_collision_axis_aligned(relative_body:Trajectory,expected_collision_time:Option<Time>){
 		let h0=HitboxMesh::new(PhysicsMesh::unit_cube(),integer::Planar64Affine3::new(mat3::from_diagonal(int3(5,1,5)>>1),vec3::zero()));
 		let h1=StyleModifiers::roblox_bhop().calculate_mesh();
 		let hitbox_mesh=h1.transformed_mesh();
 		let platform_mesh=h0.transformed_mesh();
 		let minkowski=model_physics::MinkowskiMesh::minkowski_sum(platform_mesh,hitbox_mesh);
-		let collision=minkowski.predict_collision_in(&relative_body,Time::ZERO..Time::from_secs(10)).unwrap();
+		let collision=minkowski.predict_collision_in(&relative_body,..);
 		assert_eq!(collision.map(|tup|relative_body.time+tup.1.into()),expected_collision_time,"Incorrect time of collision");
 	}
-	fn test_collision_rotated(relative_body:Body,expected_collision_time:Option<Time>){
+	fn test_collision_rotated(relative_body:Trajectory,expected_collision_time:Option<Time>){
 		let h0=HitboxMesh::new(PhysicsMesh::unit_cube(),
 			integer::Planar64Affine3::new(
 				Planar64Mat3::from_cols([
@@ -1991,16 +1992,16 @@ mod test{
 		let hitbox_mesh=h1.transformed_mesh();
 		let platform_mesh=h0.transformed_mesh();
 		let minkowski=model_physics::MinkowskiMesh::minkowski_sum(platform_mesh,hitbox_mesh);
-		let collision=minkowski.predict_collision_in(&relative_body,Time::ZERO..Time::from_secs(10)).unwrap();
+		let collision=minkowski.predict_collision_in(&relative_body,..);
 		assert_eq!(collision.map(|tup|relative_body.time+tup.1.into()),expected_collision_time,"Incorrect time of collision");
 	}
-	fn test_collision(relative_body:Body,expected_collision_time:Option<Time>){
+	fn test_collision(relative_body:Trajectory,expected_collision_time:Option<Time>){
 		test_collision_axis_aligned(relative_body,expected_collision_time);
 		test_collision_rotated(relative_body,expected_collision_time);
 	}
 	#[test]
 	fn test_collision_degenerate_straight_down(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,5,0),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2009,7 +2010,7 @@ mod test{
 	}
 	#[test]
 	fn test_collision_small_mv(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,5,0),
 			int3(0,-1,0)+(vec3::X>>32),
 			vec3::zero(),
@@ -2018,7 +2019,7 @@ mod test{
 	}
 	#[test]
 	fn test_collision_degenerate_east(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(3,5,0),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2027,7 +2028,7 @@ mod test{
 	}
 	#[test]
 	fn test_collision_degenerate_south(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,5,3),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2036,7 +2037,7 @@ mod test{
 	}
 	#[test]
 	fn test_collision_degenerate_west(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(-3,5,0),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2045,7 +2046,7 @@ mod test{
 	}
 	#[test]
 	fn test_collision_degenerate_north(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,5,-3),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2054,115 +2055,115 @@ mod test{
 	}
 	#[test]
 	fn test_collision_parabola_edge_east_from_west(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(3,3,0),
 			int3(100,-1,0),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_south_from_north(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,3,3),
 			int3(0,-1,100),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_west_from_east(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(-3,3,0),
 			int3(-100,-1,0),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_north_from_south(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,3,-3),
 			int3(0,-1,-100),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_north_from_ne(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,6,-7)>>1,
 			int3(-10,-1,1),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_north_from_nw(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,6,-7)>>1,
 			int3(10,-1,1),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_east_from_se(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(7,6,0)>>1,
 			int3(-1,-1,-10),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_east_from_ne(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(7,6,0)>>1,
 			int3(-1,-1,10),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_south_from_se(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,6,7)>>1,
 			int3(-10,-1,-1),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_south_from_sw(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,6,7)>>1,
 			int3(10,-1,-1),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_west_from_se(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(-7,6,0)>>1,
 			int3(1,-1,-10),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_parabola_edge_west_from_ne(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(-7,6,0)>>1,
 			int3(1,-1,10),
 			int3(0,-1,0),
 			Time::ZERO
-		).relative_to(&Body::ZERO).body(Time::from_secs(-1)),Some(Time::from_secs(0)));
+		).relative_to(&Trajectory::ZERO,Time::from_secs(-1)),Some(Time::from_secs(0)));
 	}
 	#[test]
 	fn test_collision_oblique(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,5,0),
 			int3(1,-64,2)>>6,// /64
 			vec3::zero(),
@@ -2171,7 +2172,7 @@ mod test{
 	}
 	#[test]
 	fn zoom_hit_nothing(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			int3(0,10,0),
 			int3(1,0,0),
 			int3(0,1,0),
@@ -2180,7 +2181,7 @@ mod test{
 	}
 	#[test]
 	fn already_inside_hit_nothing(){
-		test_collision(Body::new(
+		test_collision(Trajectory::new(
 			vec3::zero(),
 			int3(1,0,0),
 			int3(0,1,0),
@@ -2190,7 +2191,7 @@ mod test{
 	// overlap edges by 1 epsilon
 	#[test]
 	fn almost_miss_north(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(0,10,-7)>>1)+vec3::raw_xyz(0,0,1),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2199,7 +2200,7 @@ mod test{
 	}
 	#[test]
 	fn almost_miss_east(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(7,10,0)>>1)+vec3::raw_xyz(-1,0,0),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2208,7 +2209,7 @@ mod test{
 	}
 	#[test]
 	fn almost_miss_south(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(0,10,7)>>1)+vec3::raw_xyz(0,0,-1),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2217,7 +2218,7 @@ mod test{
 	}
 	#[test]
 	fn almost_miss_west(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(-7,10,0)>>1)+vec3::raw_xyz(1,0,0),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2227,7 +2228,7 @@ mod test{
 	// exactly miss edges
 	#[test]
 	fn exact_miss_north(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			int3(0,10,-7)>>1,
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2236,7 +2237,7 @@ mod test{
 	}
 	#[test]
 	fn exact_miss_east(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			int3(7,10,0)>>1,
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2245,7 +2246,7 @@ mod test{
 	}
 	#[test]
 	fn exact_miss_south(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			int3(0,10,7)>>1,
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2254,7 +2255,7 @@ mod test{
 	}
 	#[test]
 	fn exact_miss_west(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			int3(-7,10,0)>>1,
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2264,7 +2265,7 @@ mod test{
 	// miss edges by 1 epsilon
 	#[test]
 	fn narrow_miss_north(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(0,10,-7)>>1)-vec3::raw_xyz(0,0,1),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2273,7 +2274,7 @@ mod test{
 	}
 	#[test]
 	fn narrow_miss_east(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(7,10,0)>>1)-vec3::raw_xyz(-1,0,0),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2282,7 +2283,7 @@ mod test{
 	}
 	#[test]
 	fn narrow_miss_south(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(0,10,7)>>1)-vec3::raw_xyz(0,0,-1),
 			int3(0,-1,0),
 			vec3::zero(),
@@ -2291,7 +2292,7 @@ mod test{
 	}
 	#[test]
 	fn narrow_miss_west(){
-		test_collision_axis_aligned(Body::new(
+		test_collision_axis_aligned(Trajectory::new(
 			(int3(-7,10,0)>>1)-vec3::raw_xyz(1,0,0),
 			int3(0,-1,0),
 			vec3::zero(),
--- a/engine/physics/src/push_solve.rs
+++ b/engine/physics/src/push_solve.rs
@@ -15,6 +15,7 @@ type Conts<'a>=arrayvec::ArrayVec<&'a Contact,4>;
 const RATIO_ZERO:Ratio<Fixed<1,32>,Fixed<1,32>>=Ratio::new(Fixed::ZERO,Fixed::EPSILON);

 /// Information about a contact restriction
+#[derive(Debug,PartialEq)]
 pub struct Contact{
 	pub position:Planar64Vec3,
 	pub velocity:Planar64Vec3,
@@ -281,16 +282,16 @@ fn get_first_touch<'a>(contacts:&'a [Contact],ray:&Ray,conts:&Conts)->Option<(Ra
 		.min_by_key(|&(t,_)|t)
 }

-pub fn push_solve(contacts:&[Contact],point:Planar64Vec3)->Planar64Vec3{
+pub fn push_solve(contacts:&[Contact],point:Planar64Vec3)->(Planar64Vec3,Conts<'_>){
 	let (mut ray,mut conts)=get_best_push_ray_and_conts_0(point);
 	loop{
 		let (next_t,next_cont)=match get_first_touch(contacts,&ray,&conts){
 			Some((t,cont))=>(t,cont),
-			None=>return ray.origin,
+			None=>return (ray.origin,conts),
 		};

 		if RATIO_ZERO.le_ratio(next_t){
-			return ray.origin;
+			return (ray.origin,conts);
 		}

 		//push_front
@@ -306,7 +307,7 @@ pub fn push_solve(contacts:&[Contact],point:Planar64Vec3)->Planar64Vec3{
 		let meet_point=ray.extrapolate(next_t);
 		match get_best_push_ray_and_conts(meet_point,conts.as_slice()){
 			Some((new_ray,new_conts))=>(ray,conts)=(new_ray,new_conts),
-			None=>return meet_point,
+			None=>return (meet_point,conts),
 		}
 	}
 }
@@ -323,9 +324,8 @@ mod tests{
 				normal:vec3::Y,
 			}
 		];
-		assert_eq!(
-			vec3::zero(),
-			push_solve(&contacts,vec3::NEG_Y)
-		);
+		let (point,conts)=push_solve(&contacts,vec3::NEG_Y);
+		assert_eq!(point,vec3::zero());
+		assert_eq!(conts.as_slice(),[&contacts[0]].as_slice());
 	}
 }
--- a/engine/session/src/session.rs
+++ b/engine/session/src/session.rs
@@ -52,13 +52,12 @@ pub enum SessionControlInstruction{
 pub enum SessionPlaybackInstruction{
 	SkipForward,
 	SkipBack,
-	TogglePaused,
 	DecreaseTimescale,
 	IncreaseTimescale,
 }

 pub struct FrameState{
-	pub body:physics::Body,
+	pub trajectory:physics::Trajectory<'static>,
 	pub camera:physics::PhysicsCamera,
 	pub time:PhysicsTime,
 }
@@ -77,9 +76,9 @@ impl Simulation{
 			physics,
 		}
 	}
-	pub fn get_frame_state(&self,time:SessionTime)->FrameState{
+	pub fn get_frame_state(&self,time:SessionTime,data:&PhysicsData)->FrameState{
 		FrameState{
-			body:self.physics.camera_body(),
+			trajectory:self.physics.camera_trajectory(data),
 			camera:self.physics.camera(),
 			time:self.timer.time(time),
 		}
@@ -188,9 +187,9 @@ impl Session{
 	}
 	pub fn get_frame_state(&self,time:SessionTime)->Option<FrameState>{
 		match &self.view_state{
-			ViewState::Play=>Some(self.simulation.get_frame_state(time)),
+			ViewState::Play=>Some(self.simulation.get_frame_state(time,&self.geometry_shared)),
 			ViewState::Replay(bot_id)=>self.replays.get(bot_id).map(|replay|
-				replay.simulation.get_frame_state(time)
+				replay.simulation.get_frame_state(time,&self.geometry_shared)
 			),
 		}
 	}
@@ -239,12 +238,16 @@ impl InstructionConsumer<Instruction<'_>> for Session{
 				run_mouse_interpolator_instruction!(MouseInterpolatorInstruction::Mode(ModeInstruction::Reset));
 				run_mouse_interpolator_instruction!(MouseInterpolatorInstruction::Misc(MiscInstruction::SetSensitivity(self.user_settings().calculate_sensitivity())));
 				run_mouse_interpolator_instruction!(MouseInterpolatorInstruction::Mode(ModeInstruction::Restart(mode_id)));
+				// TODO: think about this harder.  This works around a bug where you fall infinitely when you reset.
+				self.simulation.timer.set_time(ins.time,PhysicsTime::ZERO);
 			},
 			Instruction::Input(SessionInputInstruction::Mode(ImplicitModeInstruction::ResetAndSpawn(mode_id,spawn_id)))=>{
 				self.clear_recording();
 				run_mouse_interpolator_instruction!(MouseInterpolatorInstruction::Mode(ModeInstruction::Reset));
 				run_mouse_interpolator_instruction!(MouseInterpolatorInstruction::Misc(MiscInstruction::SetSensitivity(self.user_settings().calculate_sensitivity())));
 				run_mouse_interpolator_instruction!(MouseInterpolatorInstruction::Mode(ModeInstruction::Spawn(mode_id,spawn_id)));
+				// TODO: think about this harder.  This works around a bug where you fall infinitely when you reset.
+				self.simulation.timer.set_time(ins.time,PhysicsTime::ZERO);
 			},
 			Instruction::Input(SessionInputInstruction::Misc(misc_instruction))=>{
 				run_mouse_interpolator_instruction!(MouseInterpolatorInstruction::Misc(misc_instruction));
@@ -253,7 +256,14 @@ impl InstructionConsumer<Instruction<'_>> for Session{
 				// don't flush the buffered instructions in the mouse interpolator
 				// until the mouse is confirmed to be not moving at a later time
 				// what if they pause for 5ms lmao
-				_=self.simulation.timer.set_paused(ins.time,paused);
+				match &self.view_state{
+					ViewState::Play=>{
+						_=self.simulation.timer.set_paused(ins.time,paused);
+					},
+					ViewState::Replay(bot_id)=>if let Some(replay)=self.replays.get_mut(bot_id){
+						_=replay.simulation.timer.set_paused(ins.time,paused);
+					},
+				}
 			},
 			Instruction::Control(SessionControlInstruction::CopyRecordingIntoReplayAndSpectate)=> if let ViewState::Play=self.view_state{
 				// Bind: B
@@ -374,14 +384,6 @@ impl InstructionConsumer<Instruction<'_>> for Session{
 					},
 				}
 			},
-			Instruction::Playback(SessionPlaybackInstruction::TogglePaused)=>{
-				match &self.view_state{
-					ViewState::Play=>(),
-					ViewState::Replay(bot_id)=>if let Some(replay)=self.replays.get_mut(bot_id){
-						_=replay.simulation.timer.set_paused(ins.time,!replay.simulation.timer.is_paused());
-					},
-				}
-			}
 			Instruction::ChangeMap(complete_map)=>{
 				self.clear_recording();
 				self.change_map(complete_map);
--- a/integration-testing/src/main.rs
+++ b/integration-testing/src/main.rs
@@ -71,16 +71,16 @@ fn segment_determinism(bot:strafesnet_snf::bot::Segment,physics_data:&PhysicsDat
 	for (i,ins) in bot.instructions.into_iter().enumerate(){
 		let state_deterministic=physics_deterministic.clone();
 		let state_filtered=physics_filtered.clone();
-		PhysicsContext::run_input_instruction(&mut physics_deterministic,&physics_data,ins.clone());
+		PhysicsContext::run_input_instruction(&mut physics_deterministic,physics_data,ins.clone());
 		match ins{
 			strafesnet_common::instruction::TimedInstruction{instruction:strafesnet_common::physics::Instruction::Idle,..}=>(),
 			other=>{
 				non_idle_count+=1;
 				// run
-				PhysicsContext::run_input_instruction(&mut physics_filtered,&physics_data,other.clone());
+				PhysicsContext::run_input_instruction(&mut physics_filtered,physics_data,other.clone());
 				// check if position matches
-				let b0=physics_deterministic.camera_body();
-				let b1=physics_filtered.camera_body();
+				let b0=physics_deterministic.camera_trajectory(physics_data);
+				let b1=physics_filtered.camera_trajectory(physics_data);
 				if b0.position!=b1.position{
 					let nanoseconds=start.elapsed().as_nanos() as u64;
 					println!("desync at instruction #{}",i);
--- a/integration-testing/src/test_scenes.rs
+++ b/integration-testing/src/test_scenes.rs
@@ -73,7 +73,6 @@ fn simultaneous_collision(){
 	let body=strafesnet_physics::physics::Body::new(
 		(vec3::int(5+2,0,0)>>1)+vec3::int(1,1,0),
 		vec3::int(-1,-1,0),
-		vec3::int(0,0,0),
 		Time::ZERO,
 	);
 	let mut physics=PhysicsState::new_with_body(body);
@@ -88,7 +87,6 @@ fn simultaneous_collision(){
 	let body=physics.body();
 	assert_eq!(body.position,vec3::int(5,0,0));
 	assert_eq!(body.velocity,vec3::int(0,0,0));
-	assert_eq!(body.acceleration,vec3::int(0,0,0));
 	assert_eq!(body.time,Time::from_secs(1));
 }
 #[test]
@@ -97,7 +95,6 @@ fn bug_3(){
 	let body=strafesnet_physics::physics::Body::new(
 		(vec3::int(5+2,0,0)>>1)+vec3::int(1,2,0),
 		vec3::int(-1,-1,0),
-		vec3::int(0,0,0),
 		Time::ZERO,
 	);
 	let mut physics=PhysicsState::new_with_body(body);
@@ -112,43 +109,5 @@ fn bug_3(){
 	let body=physics.body();
 	assert_eq!(body.position,vec3::int(5+2,0,0)>>1);
 	assert_eq!(body.velocity,vec3::int(0,0,0));
-	assert_eq!(body.acceleration,vec3::int(0,0,0));
-	assert_eq!(body.time,Time::from_secs(2));
-}
-
-fn test_scene_cylinder()->PhysicsData{
-	let mut builder=TestSceneBuilder::new();
-	let cube_face_description=CubeFaceDescription::new(Default::default(),RenderConfigId::new(0));
-	let mesh=builder.push_mesh(strafesnet_rbx_loader::primitives::unit_cylinder(cube_face_description));
-	// place one 5x5x5 cylinder.
-	builder.push_mesh_instance(mesh,Planar64Affine3::new(
-		mat3::from_diagonal(vec3::int(5,5,5)>>1),
-		vec3::int(0,-5,0)
-	));
-	builder.build()
-}
-
-#[test]
-fn test_minimum_difference(){
-	let physics_data=test_scene_cylinder();
-	let body=strafesnet_physics::physics::Body::new(
-		vec3::int(4,1,4)>>1,
-		vec3::int(-1,-1,-2),
-		vec3::int(0,-100,0),
-		Time::ZERO,
-	);
-	let mut physics=PhysicsState::new_with_body(body);
-	physics.style_mut().gravity=vec3::zero();
-	let mut phys_iter=PhysicsContext::iter_internal(&mut physics,&physics_data,Time::from_secs(3))
-		.filter(|ins|!matches!(ins.instruction,InternalInstruction::StrafeTick));
-	// touch side of part at 0,0,0
-	assert_eq!(phys_iter.next().unwrap().time,Time::from_secs(1));
-	// touch top of part at 5,-5,0
-	assert_eq!(phys_iter.next().unwrap().time,Time::from_secs(2));
-	assert!(phys_iter.next().is_none());
-	let body=physics.body();
-	assert_eq!(body.position,vec3::int(5+2,0,0)>>1);
-	assert_eq!(body.velocity,vec3::int(0,0,0));
-	assert_eq!(body.acceleration,vec3::int(0,0,0));
 	assert_eq!(body.time,Time::from_secs(2));
 }
--- a/integration-testing/src/tests.rs
+++ b/integration-testing/src/tests.rs
@@ -22,7 +22,6 @@ fn physics_bug_2()->Result<(),ReplayError>{
 	let body=strafesnet_physics::physics::Body::new(
 		vec3::raw_xyz(555690659654,1490485868773,1277783839382),
 		vec3::int(0,0,0),
-		vec3::int(0,-100,0),
 		Time::ZERO,
 	);
 	let mut physics=PhysicsState::new_with_body(body);
@@ -60,45 +59,12 @@ fn physics_bug_3()->Result<(),ReplayError>{
 		// vec3::raw_xyz(0,-96915585363,1265),
 		// vec3::raw_xyz(0,-429496729600,0),
 		// corner setup before wall hits
-		vec3::raw_xyz(-1392580080675,3325402529458,-2444727738679),
-		vec3::raw_xyz(-30259028820,-22950929553,-71141663007),
-		vec3::raw_xyz(0,-429496729600,0),
-		Time::ZERO,
-	);
-	let mut physics=PhysicsState::new_with_body(body);
-	// wait one second to activate the bug
-	PhysicsContext::run_input_instruction(&mut physics,&physics_data,strafesnet_common::instruction::TimedInstruction{
-		time:Time::from_millis(500),
-		instruction:strafesnet_common::physics::Instruction::Idle,
-	});
-
-	Ok(())
-}
-
-// Infinite loop! body=p(-1796.657, 677.618, 36.959) v(3.158, -53.650, -34.435) a(-0.000, -71.276, -45.248) t(288s+440000000ns)
-// Infinite loop! body=p(-2382.440, 160.150, -379.151) v(53.632, 35.779, 44.904) a(0.000, -100.000, 0.000) t(306s+675758543ns)
-// Infinite loop! body=p(-1798.724, 731.459, 68.784) v(-17.389, 0.000, -78.087) a(0.000, 0.000, 0.000) t(284s+006980061ns)
-// Infinite loop! body=p(-1796.657, 677.618, 36.959) v(3.158, -53.650, -34.435) a(-0.000, -71.276, -45.248) t(288s+440000000ns)
-// Infinite loop! body=p(-1797.504, 738.529, 74.864) v(-3.653, 0.000, -79.917) a(0.000, 0.000, 0.000) t(282s+709871336ns)
-// Infinite loop! body=p(-1797.569, 735.449, 71.859) v(23.726, -76.309, -3.747) a(0.000, 0.000, 0.000) t(283s+325193187ns)
-
-#[test]
-fn physics_md_infinite_loop()->Result<(),ReplayError>{
-	println!("loading map file..");
-	let data=read_entire_file("../tools/bhop_maps/5692113331.snfm")?;
-	let map=strafesnet_snf::read_map(data)?.into_complete_map()?;
-
-	// create recording
-	println!("generating models..");
-	let physics_data=PhysicsData::new(&map);
-	println!("simulating...");
-
-	//teleport to bug
-	use strafesnet_common::integer::{vec3,Time};
-	let body=strafesnet_physics::physics::Body::new(
-		vec3::try_from_f32_array([-1796.657, 677.618, 36.959]).unwrap(),
-		vec3::try_from_f32_array([3.158, -53.650, -34.435]).unwrap(),
-		vec3::int(0,-100,0),
+		// vec3::raw_xyz(-1392580080675,3325402529458,-2444727738679),
+		// vec3::raw_xyz(-30259028820,-22950929553,-71141663007),
+		// vec3::raw_xyz(0,-429496729600,0),
+		// Actual bug 3 repro
+		vec3::raw_xyz(-2505538624455,3357963283914,557275711118),
+		vec3::raw_xyz(204188283920,-282280474198,166172785440),
 		Time::ZERO,
 	);
 	let mut physics=PhysicsState::new_with_body(body);
--- a/lib/common/src/physics.rs
+++ b/lib/common/src/physics.rs
@@ -36,6 +36,7 @@ pub enum SetControlInstruction{
 	SetMoveForward(bool),
 	SetJump(bool),
 	SetZoom(bool),
+	SetSprint(bool),
 }
 #[derive(Clone,Debug)]
 pub enum ModeInstruction{
--- a/lib/rbx_loader/Cargo.toml
+++ b/lib/rbx_loader/Cargo.toml
@@ -12,7 +12,7 @@ authors = ["Rhys Lloyd <krakow20@gmail.com>"]
 [dependencies]
 bytemuck = "1.14.3"
 glam = "0.30.0"
-regex = { version = "1.11.3", default-features = false }
+regex = { version = "1.11.3", default-features = false, features = ["unicode-perl"] }
 rbx_mesh = "0.5.0"
 rbxassetid = { version = "0.1.0", path = "../rbxassetid", registry = "strafesnet" }
 roblox_emulator = { version = "0.5.1", path = "../roblox_emulator", default-features = false, registry = "strafesnet" }
--- a/lib/snf/src/newtypes/physics.rs
+++ b/lib/snf/src/newtypes/physics.rs
@@ -88,6 +88,11 @@ pub enum Instruction{
 	PracticeFly,
 	#[brw(magic=14u8)]
 	SetSensitivity(super::integer::Ratio64Vec2),
+	#[brw(magic=15u8)]
+	SetSprint(
+		#[br(map=bool_from_u8)]
+		#[bw(map=bool_into_u8)]
+		bool),
 	#[brw(magic=255u8)]
 	Idle,
 }
@@ -116,6 +121,7 @@ impl TryInto<strafesnet_common::physics::Instruction> for Instruction{
 			Instruction::SetMoveForward(state)=>strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetMoveForward(state.into())),
 			Instruction::SetJump(state)=>strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetJump(state.into())),
 			Instruction::SetZoom(state)=>strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetZoom(state.into())),
+			Instruction::SetSprint(state)=>strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetSprint(state.into())),
 			Instruction::Reset=>strafesnet_common::physics::Instruction::Mode(strafesnet_common::physics::ModeInstruction::Reset),
 			Instruction::Restart(mode_id)=>strafesnet_common::physics::Instruction::Mode(strafesnet_common::physics::ModeInstruction::Restart(strafesnet_common::gameplay_modes::ModeId::new(mode_id))),
 			Instruction::Spawn(mode_id,stage_id)=>strafesnet_common::physics::Instruction::Mode(strafesnet_common::physics::ModeInstruction::Spawn(
@@ -142,6 +148,7 @@ impl TryFrom<strafesnet_common::physics::Instruction> for Instruction{
 			strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetMoveForward(state))=>Ok(Instruction::SetMoveForward(state.into())),
 			strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetJump(state))=>Ok(Instruction::SetJump(state.into())),
 			strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetZoom(state))=>Ok(Instruction::SetZoom(state.into())),
+			strafesnet_common::physics::Instruction::SetControl(strafesnet_common::physics::SetControlInstruction::SetSprint(state))=>Ok(Instruction::SetSprint(state.into())),
 			strafesnet_common::physics::Instruction::Mode(strafesnet_common::physics::ModeInstruction::Reset)=>Ok(Instruction::Reset),
 			strafesnet_common::physics::Instruction::Mode(strafesnet_common::physics::ModeInstruction::Restart(mode_id))=>Ok(Instruction::Restart(mode_id.get())),
 			strafesnet_common::physics::Instruction::Mode(strafesnet_common::physics::ModeInstruction::Spawn(mode_id,stage_id))=>Ok(Instruction::Spawn(
--- a/strafe-client/models/suzanne.obj
+++ b/strafe-client/models/suzanne.obj
--- a/strafe-client/models/teapot.obj
+++ b/strafe-client/models/teapot.obj
--- a/strafe-client/models/teslacyberv3.0.mtl
+++ b/strafe-client/models/teslacyberv3.0.mtl
@@ -1,62 +0,0 @@
-# Blender MTL File: 'teslacyberv3.0.blend'
-# Material Count: 6
-
-newmtl Material
-Ns 65.476285
-Ka 1.000000 1.000000 1.000000
-Kd 0.411568 0.411568 0.411568
-Ks 0.614679 0.614679 0.614679
-Ke 0.000000 0.000000 0.000000
-Ni 36.750000
-d 1.000000
-illum 3
-
-newmtl Материал
-Ns 323.999994
-Ka 1.000000 1.000000 1.000000
-Kd 0.800000 0.800000 0.800000
-Ks 0.500000 0.500000 0.500000
-Ke 0.000000 0.000000 0.000000
-Ni 1.000000
-d 1.000000
-illum 2
-
-newmtl Материал.001
-Ns 900.000000
-Ka 1.000000 1.000000 1.000000
-Kd 0.026240 0.026240 0.026240
-Ks 0.000000 0.000000 0.000000
-Ke 0.000000 0.000000 0.000000
-Ni 1.450000
-d 1.000000
-illum 1
-
-newmtl Материал.002
-Ns 0.000000
-Ka 1.000000 1.000000 1.000000
-Kd 0.031837 0.032429 0.029425
-Ks 0.169725 0.169725 0.169725
-Ke 0.000000 0.000000 0.000000
-Ni 0.000000
-d 1.000000
-illum 2
-
-newmtl Материал.003
-Ns 900.000000
-Ka 1.000000 1.000000 1.000000
-Kd 0.023585 0.083235 0.095923
-Ks 1.000000 1.000000 1.000000
-Ke 0.000000 0.000000 0.000000
-Ni 45.049999
-d 1.000000
-illum 3
-
-newmtl Материал.004
-Ns 323.999994
-Ka 1.000000 1.000000 1.000000
-Kd 0.800000 0.800000 0.800000
-Ks 0.500000 0.500000 0.500000
-Ke 0.000000 0.000000 0.000000
-Ni 1.000000
-d 1.000000
-illum 2
--- a/strafe-client/models/teslacyberv3.0.obj
+++ b/strafe-client/models/teslacyberv3.0.obj
--- a/strafe-client/src/window.rs
+++ b/strafe-client/src/window.rs
@@ -15,6 +15,7 @@ pub enum Instruction{
 struct WindowContext<'a>{
 	manual_mouse_lock:bool,
 	mouse_pos:glam::DVec2,
+	simulation_paused:bool,
 	screen_size:glam::UVec2,
 	window:&'a winit::window::Window,
 	physics_thread:crate::compat_worker::QNWorker<'a,TimedInstruction<PhysicsWorkerInstruction,SessionTime>>,
@@ -24,6 +25,35 @@ impl WindowContext<'_>{
 	fn get_middle_of_screen(&self)->winit::dpi::PhysicalPosition<u32>{
 		winit::dpi::PhysicalPosition::new(self.screen_size.x/2,self.screen_size.y/2)
 	}
+	fn free_mouse(&mut self){
+		self.manual_mouse_lock=false;
+		match self.window.set_cursor_position(self.get_middle_of_screen()){
+			Ok(())=>(),
+			Err(e)=>println!("Could not set cursor position: {:?}",e),
+		}
+		match self.window.set_cursor_grab(winit::window::CursorGrabMode::None){
+			Ok(())=>(),
+			Err(e)=>println!("Could not release cursor: {:?}",e),
+		}
+		self.window.set_cursor_visible(true);
+	}
+	fn lock_mouse(&mut self){
+		//if cursor is outside window don't lock but apparently there's no get pos function
+		//let pos=window.get_cursor_pos();
+		match self.window.set_cursor_grab(winit::window::CursorGrabMode::Locked){
+			Ok(())=>(),
+			Err(_)=>{
+				match self.window.set_cursor_grab(winit::window::CursorGrabMode::Confined){
+					Ok(())=>(),
+					Err(e)=>{
+						self.manual_mouse_lock=true;
+						println!("Could not confine cursor: {:?}",e)
+					},
+				}
+			}
+		}
+		self.window.set_cursor_visible(false);
+	}
 	fn window_event(&mut self,time:SessionTime,event:winit::event::WindowEvent){
 		match event{
 			winit::event::WindowEvent::DroppedFile(path)=>{
@@ -34,6 +64,10 @@ impl WindowContext<'_>{
 				}
 			},
 			winit::event::WindowEvent::Focused(state)=>{
+				// don't unpause if manually paused
+				if self.simulation_paused{
+					return;
+				}
 				//pause unpause
 				self.physics_thread.send(TimedInstruction{
 					time,
@@ -46,35 +80,8 @@ impl WindowContext<'_>{
 				..
 			}=>{
 				match (logical_key,state){
-					(winit::keyboard::Key::Named(winit::keyboard::NamedKey::Tab),winit::event::ElementState::Pressed)=>{
-						self.manual_mouse_lock=false;
-						match self.window.set_cursor_position(self.get_middle_of_screen()){
-							Ok(())=>(),
-							Err(e)=>println!("Could not set cursor position: {:?}",e),
-						}
-						match self.window.set_cursor_grab(winit::window::CursorGrabMode::None){
-							Ok(())=>(),
-							Err(e)=>println!("Could not release cursor: {:?}",e),
-						}
-						self.window.set_cursor_visible(state.is_pressed());
-					},
-					(winit::keyboard::Key::Named(winit::keyboard::NamedKey::Tab),winit::event::ElementState::Released)=>{
-						//if cursor is outside window don't lock but apparently there's no get pos function
-						//let pos=window.get_cursor_pos();
-						match self.window.set_cursor_grab(winit::window::CursorGrabMode::Locked){
-							Ok(())=>(),
-							Err(_)=>{
-								match self.window.set_cursor_grab(winit::window::CursorGrabMode::Confined){
-									Ok(())=>(),
-									Err(e)=>{
-										self.manual_mouse_lock=true;
-										println!("Could not confine cursor: {:?}",e)
-									},
-								}
-							}
-						}
-						self.window.set_cursor_visible(state.is_pressed());
-					},
+					(winit::keyboard::Key::Named(winit::keyboard::NamedKey::Tab),winit::event::ElementState::Pressed)=>self.free_mouse(),
+					(winit::keyboard::Key::Named(winit::keyboard::NamedKey::Tab),winit::event::ElementState::Released)=>self.lock_mouse(),
 					(winit::keyboard::Key::Named(winit::keyboard::NamedKey::F11),winit::event::ElementState::Pressed)=>{
 						if self.window.fullscreen().is_some(){
 							self.window.set_fullscreen(None);
@@ -131,8 +138,18 @@ impl WindowContext<'_>{

 						if let Some(session_instruction)=match keycode{
 							winit::keyboard::Key::Named(winit::keyboard::NamedKey::Space)=>input_ctrl!(SetJump,s),
+							winit::keyboard::Key::Named(winit::keyboard::NamedKey::Shift)=>input_ctrl!(SetSprint,s),
 							// TODO: bind system so playback pausing can use spacebar
-							winit::keyboard::Key::Named(winit::keyboard::NamedKey::Enter)=>session_playback!(TogglePaused,s),
+							winit::keyboard::Key::Named(winit::keyboard::NamedKey::Enter)=>if s{
+								let paused=!self.simulation_paused;
+								self.simulation_paused=paused;
+								if paused{
+									self.free_mouse();
+								}else{
+									self.lock_mouse();
+								}
+								Some(SessionInstructionSubset::Control(SessionControlInstruction::SetPaused(paused)))
+							}else{None},
 							winit::keyboard::Key::Named(winit::keyboard::NamedKey::ArrowUp)=>session_playback!(IncreaseTimescale,s),
 							winit::keyboard::Key::Named(winit::keyboard::NamedKey::ArrowDown)=>session_playback!(DecreaseTimescale,s),
 							winit::keyboard::Key::Named(winit::keyboard::NamedKey::ArrowLeft)=>session_playback!(SkipBack,s),
@@ -241,6 +258,7 @@ pub fn worker<'a>(
 	let mut window_context=WindowContext{
 		manual_mouse_lock:false,
 		mouse_pos:glam::DVec2::ZERO,
+		simulation_paused:false,
 		//make sure to update this!!!!!
 		screen_size,
 		window,
Author	SHA1	Message	Date
Rhys Lloyd	b4e1678b48	introduce lifetime of body	2026-01-27 10:35:32 -08:00
Rhys Lloyd	170e2b9bce	return used contacts from push_solve	2026-01-27 09:28:26 -08:00
Rhys Lloyd	3e0fc54852	Delete Body.acceleration Field (#30 ) Acceleration is not a persistent part of the PhysicsState, and is only used for intermediate calculations along a trajectory. Fixes several bugs: - Walk decelerate clip into wall - Walk accelerate clip into wall - Fall while flying Reviewed-on: #30 Co-authored-by: Rhys Lloyd <krakow20@gmail.com> Co-committed-by: Rhys Lloyd <krakow20@gmail.com>	2026-01-27 17:08:08 +00:00
Rhys Lloyd	acea52646a	untab	2026-01-27 07:58:18 -08:00
Rhys Lloyd	7220506fd5	plumb sprint	2026-01-27 07:46:17 -08:00
Rhys Lloyd	8f94234ddc	change DirectedEdge signature	2026-01-27 07:38:45 -08:00
Rhys Lloyd	36143b8b69	change UndirectedEdge signature	2026-01-27 07:35:43 -08:00
Rhys Lloyd	3893b2f44f	work around reset bug	2026-01-26 09:19:31 -08:00
Rhys Lloyd	d62ff68baa	fix comments	2026-01-26 09:06:40 -08:00
Rhys Lloyd	2331bef281	pretty print time	2026-01-22 09:43:35 -08:00
Quaternions	31b52f7c34	Conditionally Advance Body in `atomic_internal_instruction` StrafeTick (#14 ) Closes #13, but exposes the underlying issue at all times. Reviewed-on: #14 Co-authored-by: Quaternions <krakow20@gmail.com> Co-committed-by: Quaternions <krakow20@gmail.com>	2026-01-22 17:00:52 +00:00
Rhys Lloyd	b12c495a33	it: bug 3	2026-01-22 08:57:35 -08:00
Rhys Lloyd	8329eadb18	use unbounded range in physics tests	2026-01-22 08:47:54 -08:00
Rhys Lloyd	4b2f93be66	fix algorithm setup start position	2026-01-22 08:41:54 -08:00
Rhys Lloyd	469ab48156	allow unbounded range	2026-01-22 08:41:35 -08:00
Rhys Lloyd	c2650adf54	md: simplify reduce	2026-01-21 10:32:19 -08:00
Rhys Lloyd	cdafbb4077	Implement MinimumDifference Algorithm (#25 ) Completely replace the janky closest fev crawl from infinity algorithm with a dedicated purpose-built algorithm. Finding the closest point on a MinkowskiMesh is equivalent to finding the closest point between two meshes. Reviewed-on: #25 Co-authored-by: Rhys Lloyd <krakow20@gmail.com> Co-committed-by: Rhys Lloyd <krakow20@gmail.com>	2026-01-21 17:31:52 +00:00
Rhys Lloyd	087e95b1f7	delete TogglePaused	2025-12-22 13:54:35 -08:00
Rhys Lloyd	e46a51319f	delete unused models	2025-12-20 16:31:05 -08:00
Rhys Lloyd	a3b0306430	rbx_loader: fix regex	2025-12-19 13:10:04 -08:00