diff --git a/src/bin/wireframe/scene.rs b/src/bin/wireframe/scene.rs
index a938b37..eac5a5d 100644
--- a/src/bin/wireframe/scene.rs
+++ b/src/bin/wireframe/scene.rs
@@ -58,6 +58,18 @@ fn draw_ellipse(center: Vec3, u: Vec3, v: Vec3) -> Line {
 	)
 }
 
+fn draw_mark(pos: Vec3) -> Vec<Line> {
+	[
+		vec3(1., 1., 1.),
+		vec3(1., 1., -1.),
+		vec3(1., -1., 1.),
+		vec3(1., -1., -1.),
+	]
+	.into_iter()
+	.map(|off| draw_line(pos - off, pos + off))
+	.collect()
+}
+
 pub fn build() -> Vec<FancyLine> {
 	let tube = Tube {
 		inner_radius: 30.0,
@@ -104,11 +116,17 @@ pub fn build() -> Vec<FancyLine> {
 fn draw_ray_2(gc: &mut Vec<Line>, space: &Space, camera: Location, dir: Vec3) {
 	let pos = vec3(0., 0., 0.);
 	let (hits, path) = space.trace_dbg(camera, Ray { pos, dir });
-	let hits2 = space.trace(camera, Ray { pos, dir });
-	for (a, b) in hits.into_iter().zip(hits2.into_iter()) {
-		assert_eq!(a.id, b.id);
-		assert_eq!(a.pos, b.pos);
-		assert_eq!(a.rel, b.rel);
+	if true {
+		let hits2 = space.trace(camera, Ray { pos, dir });
+		for (a, b) in hits.iter().zip(hits2.into_iter()) {
+			assert_eq!(a.id, b.id);
+			assert_eq!(a.pos, b.pos);
+			assert_eq!(a.rel, b.rel);
+		}
+	}
+
+	for hit in hits {
+		gc.extend(draw_mark(hit.pos));
 	}
 
 	let mut pts = path.points;