diff --git a/src/anim.rs b/src/anim.rs
index 94f8840..56dbd58 100644
--- a/src/anim.rs
+++ b/src/anim.rs
@@ -59,9 +59,7 @@ impl SphereParams {
 			center,
 			radius,
 			emit_color,
-			pad1: 0.0,
 			reflect_color,
-			pad2: 0.0,
 		}
 	}
 }
diff --git a/src/trace.rs b/src/trace.rs
index a7ab316..be0d84f 100644
--- a/src/trace.rs
+++ b/src/trace.rs
@@ -12,15 +12,13 @@ pub struct Params {
 	pub sphere_count: u32,
 }
 
-#[derive(Debug, Clone, Copy, Pod, Zeroable)]
+#[derive(Debug, Clone, Copy)]
 #[repr(C)]
 pub struct Sphere {
 	pub center: Vec3,
 	pub radius: f32,
 	pub emit_color: Vec3,
-	pub pad1: f32,
 	pub reflect_color: Vec3,
-	pub pad2: f32,
 }
 
 #[derive(Debug, Clone, Copy, Pod, Zeroable)]
@@ -31,6 +29,17 @@ pub struct Vertex {
 	pub screen: Vec2,
 }
 
+#[derive(Debug, Clone, Copy, Pod, Zeroable)]
+#[repr(C)]
+struct SphereData {
+	center: Vec3,
+	radius: f32,
+	emit_color: Vec3,
+	pad1: f32,
+	reflect_color: Vec3,
+	pad2: f32,
+}
+
 pub struct Tracer {
 	view_buf: wgpu::Buffer,
 	params_buf: wgpu::Buffer,
@@ -138,9 +147,20 @@ 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,
+				pad2: 0.0,
+			})
+			.collect();
 		let spheres_buf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
 			label: None,
-			contents: cast_slice(spheres),
+			contents: cast_slice(&spheres),
 			usage: wgpu::BufferUsages::STORAGE,
 		});
 		let bindings = device.create_bind_group(&wgpu::BindGroupDescriptor {