diff --git a/src/bin/flat.rs b/src/bin/flat.rs
index a28b6a2..f397495 100644
--- a/src/bin/flat.rs
+++ b/src/bin/flat.rs
@@ -33,7 +33,16 @@ pub fn main() {
 				external_halflength: 300.0,
 			};
 
-			let space = Space { rect: tube };
+			let objs: Vec<_> = [-1.25, -1.00, -0.85, -0.50, 0.00, 0.40, 0.70, 0.95, 1.05]
+				.iter()
+				.enumerate()
+				.map(|(k, y)| Object {
+					id: k as i32,
+					loc: Location { pos: vec2(0.0, y * tube.external_halflength), rot: Mat2::IDENTITY },
+					r: 20.0,
+				})
+				.collect();
+			let space = Space { rect: tube, objs };
 
 			gc.canvas_height(1000.0);
 			tube.render(gc);
@@ -46,8 +55,8 @@ pub fn main() {
 			draw_track(gc, &space, vec2(-500.0, 0.0), vec2(1.0, 0.5));
 			draw_track(gc, &space, vec2(-0.5 * tube.inner_radius, -1.25 * tube.external_halflength), vec2(0.1, 1.0));
 
-			for y in [-1.25, -1.00, -0.85, -0.50, 0.00, 0.40, 0.70, 0.95, 1.05] {
-				let pos = vec2(0.0, y * tube.external_halflength);
+			for obj in &space.objs {
+				let pos = obj.loc.pos;
 				gc.new_path();
 				gc.circle(pos.x, pos.y, 5.0);
 				gc.fill_color(Color::Rgba(0.0, 0.5, 1.0, 1.0));
@@ -55,21 +64,23 @@ pub fn main() {
 
 				gc.stroke_color(Color::Rgba(0.0, 0.0, 0.0, 0.5));
 				draw_loop(gc, itertools_num::linspace(0.0, 2.0 * PI, 32).skip(1).map(|φ| {
-					let dir = Vec2::from_angle(φ) * 20.0;
+					let dir = Vec2::from_angle(φ) * obj.r;
 					let dir = space.flat_to_global(pos, dir);
 					pos + dir
 				}));
 				gc.stroke_color(Color::Rgba(0.0, 0.5, 1.0, 0.5));
 				draw_loop(gc, itertools_num::linspace(0.0, 2.0 * PI, 32).skip(1).map(|φ| {
-					let dir = Vec2::from_angle(φ) * 20.0;
+					let dir = Vec2::from_angle(φ) * obj.r;
 					let dir = space.flat_to_global(pos, dir);
 					space.trace_step(Ray { pos, dir }).pos
 				}));
 				gc.stroke_color(Color::Rgba(0.5, 0.0, 1.0, 1.0));
 				draw_loop(gc, itertools_num::linspace(0.0, 2.0 * PI, 32).skip(1).map(|φ| {
+					let n = obj.r.floor();
+					let d = obj.r / n;
 					let dir = Vec2::from_angle(φ);
-					let dir = space.flat_to_global(pos, dir);
-					space.trace_iter(Ray { pos, dir }).nth(20).unwrap().pos
+					let dir = space.flat_to_global(pos, dir) * d;
+					space.trace_iter(Ray { pos, dir }).nth(n as usize).unwrap().pos
 				}));
 			}
 		});
@@ -83,8 +94,15 @@ struct Location {
 	rot: Mat2,
 }
 
+struct Object {
+	id: i32,
+	loc: Location,
+	r: f32,
+}
+
 struct Space {
 	rect: Rect,
+	objs: Vec<Object>,
 }
 
 #[derive(PartialEq, Eq, Debug)]