diff --git a/src/bin/minitracer/trace.rs b/src/bin/minitracer/trace.rs
index d9f98ee..db42ceb 100644
--- a/src/bin/minitracer/trace.rs
+++ b/src/bin/minitracer/trace.rs
@@ -41,6 +41,19 @@ struct SphereData {
 	glossiness: f32,
 }
 
+impl From<&Sphere> for SphereData {
+	fn from(s: &Sphere) -> Self {
+		SphereData {
+			center: s.center,
+			radius: s.radius,
+			emit_color: s.emit_color,
+			pad1: 0.0,
+			reflect_color: s.reflect_color,
+			glossiness: s.glossiness,
+		}
+	}
+}
+
 pub struct Tracer {
 	view_buf: wgpu::Buffer,
 	pipeline: wgpu::RenderPipeline,
@@ -192,17 +205,7 @@ impl Tracer {
 
 impl TracerData {
 	pub fn new(device: &wgpu::Device, tracer: &Tracer, spheres: &[Sphere]) -> Self {
-		let spheres: Vec<_> = spheres
-			.iter()
-			.map(|s| SphereData {
-				center: s.center,
-				radius: s.radius,
-				emit_color: s.emit_color,
-				pad1: 0.0,
-				reflect_color: s.reflect_color,
-				glossiness: s.glossiness,
-			})
-			.collect();
+		let spheres: Vec<_> = spheres.iter().map(SphereData::from).collect();
 		let spheres_buf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
 			label: None,
 			contents: cast_slice(&spheres),