Cycles volume: fast empty space optimization by generating a tight mesh

around the volume.

We generate a tight mesh around the active voxels of the volume in order
to effectively skip empty space, and start volume ray marching as close
to interesting volume data as possible. See code comments for details on
how the mesh generation algorithm works.

This gives up to 2x speedups in some scenes.

Reviewed by: brecht, dingto

Reviewers: #cycles

Subscribers: lvxejay, jtheninja, brecht

Differential Revision: https://developer.blender.org/D3038

1 files changed, 10 insertions, 0 deletions

diff --git a/intern/cycles/render/image.cpp b/intern/cycles/render/image.cpp
index de46599e1db..9c5e32e8219 100644
--- a/intern/cycles/render/image.cpp
+++ b/intern/cycles/render/image.cpp
@@ -84,6 +84,16 @@ bool ImageManager::set_animation_frame_update(int frame)
 	return false;
 }
 
+device_memory *ImageManager::image_memory(int flat_slot)
+{
+	   ImageDataType type;
+	   int slot = flattened_slot_to_type_index(flat_slot, &type);
+
+	   Image *img = images[type][slot];
+
+	   return img->mem;
+}
+
 bool ImageManager::get_image_metadata(const string& filename,
                                       void *builtin_data,
                                       ImageMetaData& metadata)