diff --git a/src/bin/minitracer/trace.wgsl b/src/bin/minitracer/trace.wgsl
index bd22c1c..6b6df27 100644
--- a/src/bin/minitracer/trace.wgsl
+++ b/src/bin/minitracer/trace.wgsl
@@ -69,8 +69,8 @@ fn to_sphere(center: vec3f, radius: f32, t: ptr<function, f32>) -> bool {
 fn trace_fragment(in: Varying) -> vec3f {
 	seed(in.screen);
 
-	var result = vec3(0.0);
-	var color = vec3(1.0, 1.0, 1.0);
+	var result = vec3(0.);
+	var color = vec3(1.);
 	pos = params.eye;
 	let off_px = vec2(rand_float(), rand_float()) - .5;
 	let off_w = mat2x3(dpdx(in.dir), dpdy(in.dir));
@@ -94,11 +94,18 @@ fn trace_fragment(in: Varying) -> vec3f {
 		let s = spheres[sphere];
 		pos += t * ray;
 		let normal = (pos - s.center) / s.radius;
-		result += color * s.emit_color;
-		color *= s.reflect_color;
-		let diffuse = normal + rand_sphere();
-		let specular = reflect(ray, normal);
-		ray = normalize(mix(diffuse, specular, s.glossiness));
+		if (all(s.emit_color == vec3(0.))) {
+			color *= s.reflect_color;
+			let diffuse = normal + rand_sphere();
+			let specular = reflect(ray, normal);
+			ray = normalize(mix(diffuse, specular, s.glossiness));
+		} else {
+			let d = dot(-ray, normal);
+			let strength = d * d; // it would be 1 for surface emission, but this models volume emission
+			result += color * s.emit_color * strength;
+			color *= (1. - strength);
+			pos += 1e-3 * ray;
+		}
 		if (length(color) < params.min_strength) {
 			break;
 		}