Fix T54356: volume rendering bug using just color attribute.

2 files changed, 4 insertions, 44 deletions

diff --git a/intern/cycles/kernel/geom/geom_volume.h b/intern/cycles/kernel/geom/geom_volume.h
index a4e47384b25..346f228e961 100644
--- a/intern/cycles/kernel/geom/geom_volume.h
+++ b/intern/cycles/kernel/geom/geom_volume.h
@@ -68,7 +68,7 @@ ccl_device float3 volume_attribute_float3(KernelGlobals *kg, const ShaderData *s
 	if(dx) *dx = make_float3(0.0f, 0.0f, 0.0f);
 	if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
 
-	if(r.w > 1e-8f && r.w != 1.0f) {
+	if(r.w > 1e-6f && r.w != 1.0f) {
 		/* For RGBA colors, unpremultiply after interpolation. */
 		return float4_to_float3(r) / r.w;
 	}
diff --git a/intern/cycles/render/mesh_volume.cpp b/intern/cycles/render/mesh_volume.cpp
index 3571beb40d6..d1c49b456ff 100644
--- a/intern/cycles/render/mesh_volume.cpp
+++ b/intern/cycles/render/mesh_volume.cpp
@@ -495,54 +495,14 @@ void MeshManager::create_volume_mesh(Scene *scene,
 
 				for(size_t i = 0; i < voxel_grids.size(); ++i) {
 					const VoxelAttributeGrid &voxel_grid = voxel_grids[i];
+					const int channels = voxel_grid.channels;
 
-					if(voxel_grid.channels == 1) {
-						if(voxel_grid.data[voxel_index] >= isovalue) {
+					for(int c = 0; c < channels; c++) {
+						if(voxel_grid.data[voxel_index * channels + c] >= isovalue) {
 							builder.add_node_with_padding(x, y, z);
 							break;
 						}
 					}
-					else if(voxel_grid.channels == 3) {
-						voxel_index = compute_voxel_index(resolution, x*3, y, z);
-
-						if(voxel_grid.data[voxel_index] >= isovalue) {
-							builder.add_node_with_padding(x, y, z);
-							break;
-						}
-
-						if(voxel_grid.data[voxel_index + 1] >= isovalue) {
-							builder.add_node_with_padding(x, y, z);
-							break;
-						}
-
-						if(voxel_grid.data[voxel_index + 2] >= isovalue) {
-							builder.add_node_with_padding(x, y, z);
-							break;
-						}
-					}
-					else if(voxel_grid.channels == 4) {
-						voxel_index = compute_voxel_index(resolution, x*4, y, z);
-
-						/* check alpha first */
-						if(voxel_grid.data[voxel_index + 3] < isovalue) {
-							continue;
-						}
-
-						if(voxel_grid.data[voxel_index] >= isovalue) {
-							builder.add_node_with_padding(x, y, z);
-							continue;
-						}
-
-						if(voxel_grid.data[voxel_index + 1] >= isovalue) {
-							builder.add_node_with_padding(x, y, z);
-							continue;
-						}
-
-						if(voxel_grid.data[voxel_index + 2] >= isovalue) {
-							builder.add_node_with_padding(x, y, z);
-							continue;
-						}
-					}
 				}
 			}
 		}