pack material and surface indices into the fourth byte of the triangle array on the GPU. you can now take a screenshot of an image rendered with view.py() by pressing the f12 key.

1 files changed, 20 insertions, 9 deletions

diff --git a/src/kernel.cu b/src/kernel.cu
index 6c3ef1b..405f06c 100644
--- a/src/kernel.cu
+++ b/src/kernel.cu
@@ -25,11 +25,6 @@ enum
 texture<float4, 1, cudaReadModeElementType> vertices;
 __device__ uint4 *triangles;
 
-/* material/surface index lookup for each triangle */
-texture<int, 1, cudaReadModeElementType> material1_lookup;
-texture<int, 1, cudaReadModeElementType> material2_lookup;
-texture<int, 1, cudaReadModeElementType> surface_lookup;
-
 /* lower/upper bounds for the bounding box associated with each node/leaf */
 texture<float4, 1, cudaReadModeElementType> upper_bounds;
 texture<float4, 1, cudaReadModeElementType> lower_bounds;
@@ -43,6 +38,14 @@ __device__ float3 make_float3(const float4 &a)
 	return make_float3(a.x, a.y, a.z);
 }
 
+__device__ int convert(int c)
+{
+	if (c & 0x80)
+		return (0xFFFFFF00 | c);
+	else
+		return c;
+}
+
 /* Test the intersection between a ray starting at `origin` traveling in the
    direction `direction` and the bounding box around node `i`. If the ray
    intersects the bounding box return true, else return false. */
@@ -204,7 +207,7 @@ __global__ void ray_trace(int nthreads, float3 *positions, float3 *directions, i
 
 	if (triangle_index == -1)
 	{
-		pixels[id] = 0;
+		pixels[id] = 0x000000;
 	}
 	else
 	{
@@ -263,9 +266,9 @@ __global__ void propagate(int nthreads, float3 *positions, float3 *directions, f
 		float3 v1 = make_float3(tex1Dfetch(vertices, triangle_data.y));
 		float3 v2 = make_float3(tex1Dfetch(vertices, triangle_data.z));
 
-		int material_in_index = tex1Dfetch(material1_lookup, last_hit_triangle);
-		int material_out_index = tex1Dfetch(material2_lookup, last_hit_triangle);
-		int surface_index = tex1Dfetch(surface_lookup, last_hit_triangle);
+		int material_in_index = convert(0xFF & (triangle_data.w >> 24));
+		int material_out_index = convert(0xFF & (triangle_data.w >> 16));
+		int surface_index = convert(0xFF & (triangle_data.w >> 8));
 
 		float3 surface_normal = cross(v1-v0,v2-v1);
 		surface_normal /= norm(surface_normal);
@@ -408,9 +411,13 @@ __global__ void propagate(int nthreads, float3 *positions, float3 *directions, f
 			float reflection_probability = reflection_coefficient*reflection_coefficient;
 
 			if ((curand_uniform(&rng) < reflection_probability) || isnan(refracted_angle))
+			{
 				direction = rotate(surface_normal, incident_angle, p);
+			}
 			else
+			{
 				direction = rotate(surface_normal, PI-refracted_angle, p);
+			}
 
 			polarization = p;
 
@@ -422,9 +429,13 @@ __global__ void propagate(int nthreads, float3 *positions, float3 *directions, f
 			float reflection_probability = reflection_coefficient*reflection_coefficient;
 
 			if ((curand_uniform(&rng) < reflection_probability) || isnan(refracted_angle))
+			{
 				direction = rotate(surface_normal, incident_angle, p);
+			}
 			else
+			{
 				direction = rotate(surface_normal, PI-refracted_angle, p);
+			}
 
 			polarization = cross(p, direction);