diff --git a/src/bin/minitracer/main.rs b/src/bin/minitracer/main.rs
index e5d8aab..4b5c568 100644
--- a/src/bin/minitracer/main.rs
+++ b/src/bin/minitracer/main.rs
@@ -126,20 +126,7 @@ fn main() {
 					let hdr = hdr.create_view(&wgpu::TextureViewDescriptor::default());
 					let mut encoder = device.create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
 					{
-						let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
-							label: None,
-							color_attachments: &[Some(wgpu::RenderPassColorAttachment {
-								view: &hdr,
-								resolve_target: None,
-								ops: wgpu::Operations {
-									load: wgpu::LoadOp::Clear(wgpu::Color::TRANSPARENT),
-									store: wgpu::StoreOp::Store,
-								},
-							})],
-							depth_stencil_attachment: None,
-							occlusion_query_set: None,
-							timestamp_writes: None,
-						});
+						let mut render_pass = tracer.prepare(&mut encoder, &hdr);
 						for _ in 0..RAYS_PER_PIXEL {
 							frame += 1;
 							let time = frame as f32 / (60. * RAYS_PER_PIXEL as f32);
@@ -172,30 +159,15 @@ fn main() {
 							);
 						}
 					}
-					{
-						let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
-							label: None,
-							color_attachments: &[Some(wgpu::RenderPassColorAttachment {
-								view: &view,
-								resolve_target: None,
-								ops: wgpu::Operations {
-									load: wgpu::LoadOp::Clear(wgpu::Color::TRANSPARENT),
-									store: wgpu::StoreOp::Store,
-								},
-							})],
-							depth_stencil_attachment: None,
-							occlusion_query_set: None,
-							timestamp_writes: None,
-						});
-						presenter.render(
-							&device,
-							&mut render_pass,
-							&hdr,
-							present::Params {
-								divisor: RAYS_PER_PIXEL as f32,
-							},
-						);
-					}
+					presenter.render(
+						&device,
+						&mut encoder,
+						&hdr,
+						&view,
+						present::Params {
+							divisor: RAYS_PER_PIXEL as f32,
+						},
+					);
 					queue.submit(std::iter::once(encoder.finish()));
 					output.present();
 				}
diff --git a/src/bin/minitracer/present.rs b/src/bin/minitracer/present.rs
index 2cf8d84..06512d5 100644
--- a/src/bin/minitracer/present.rs
+++ b/src/bin/minitracer/present.rs
@@ -86,7 +86,7 @@ impl Presenter {
 		}
 	}
 
-	pub fn render(
+	fn render_internal(
 		&self,
 		device: &wgpu::Device,
 		pass: &mut wgpu::RenderPass,
@@ -121,4 +121,29 @@ impl Presenter {
 		pass.set_bind_group(0, &bindings, &[]);
 		pass.draw(0..4, 0..1);
 	}
+
+	pub fn render(
+		&self,
+		device: &wgpu::Device,
+		encoder: &mut wgpu::CommandEncoder,
+		source: &wgpu::TextureView,
+		target: &wgpu::TextureView,
+		params: Params,
+	) {
+		let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+			label: None,
+			color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+				view: target,
+				resolve_target: None,
+				ops: wgpu::Operations {
+					load: wgpu::LoadOp::Clear(wgpu::Color::TRANSPARENT),
+					store: wgpu::StoreOp::Store,
+				},
+			})],
+			depth_stencil_attachment: None,
+			occlusion_query_set: None,
+			timestamp_writes: None,
+		});
+		self.render_internal(device, &mut render_pass, source, params);
+	}
 }
diff --git a/src/bin/minitracer/trace.rs b/src/bin/minitracer/trace.rs
index e95c7ed..e276e2e 100644
--- a/src/bin/minitracer/trace.rs
+++ b/src/bin/minitracer/trace.rs
@@ -233,6 +233,27 @@ impl Tracer {
 		Self { view_buf, pipeline }
 	}
 
+	pub fn prepare<'encoder>(
+		&self,
+		encoder: &'encoder mut wgpu::CommandEncoder,
+		target: &wgpu::TextureView,
+	) -> wgpu::RenderPass<'encoder> {
+		encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+			label: None,
+			color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+				view: &target,
+				resolve_target: None,
+				ops: wgpu::Operations {
+					load: wgpu::LoadOp::Clear(wgpu::Color::TRANSPARENT),
+					store: wgpu::StoreOp::Store,
+				},
+			})],
+			depth_stencil_attachment: None,
+			occlusion_query_set: None,
+			timestamp_writes: None,
+		})
+	}
+
 	pub fn render(
 		&self,
 		pass: &mut wgpu::RenderPass,