forked from bartvdbraak/blender
17e7454263
There are several internal changes for this: First idea is to make __tri_verts to behave similar to __tri_storage, meaning, __tri_verts array now contains all vertices of all triangles instead of just mesh vertices. This saves some lookup when reading triangle coordinates in functions like triangle_normal(). In order to make it efficient needed to store global triangle offset somewhere. So no __tri_vindex.w contains a global triangle index which can be used to read triangle vertices. Additionally, the order of vertices in that array is aligned with primitives from BVH. This is needed to keep cache as much coherent as possible for BVH traversal. This causes some extra tricks needed to fill the array in and deal with True Displacement but those trickery is fully required to prevent noticeable slowdown. Next idea was to use this __tri_verts instead of __tri_storage in intersection code. Unfortunately, this is quite tricky to do without noticeable speed loss. Mainly this loss is caused by extra lookup happening to access vertex coordinate. Fortunately, tricks here and there (i,e, some types changes to avoid casts which are not really coming for free) reduces those losses to an acceptable level. So now they are within couple of percent only, On a positive site we've achieved: - Few percent of memory save with triangle-only scenes. Actual save in this case is close to size of all vertices. On a more fine-subdivided scenes this benefit might become more obvious. - Huge memory save of hairy scenes. For example, on koro.blend there is about 20% memory save. Similar figure for bunny.blend. This memory save was the main goal of this commit to move forward with Hair BVH which required more memory per BVH node. So while this sounds exciting, this memory optimization will become invisible by upcoming Hair BVH work. But again on a positive side, we can add an option to NOT use Hair BVH and then we'll have same-ish render times as we've got currently but will have this 20% memory benefit on hairy scenes. |
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| .. | ||
| closure | ||
| geom | ||
| kernels | ||
| osl | ||
| shaders | ||
| split | ||
| svm | ||
| CMakeLists.txt | ||
| kernel_accumulate.h | ||
| kernel_bake.h | ||
| kernel_camera.h | ||
| kernel_compat_cpu.h | ||
| kernel_compat_cuda.h | ||
| kernel_compat_opencl.h | ||
| kernel_debug.h | ||
| kernel_differential.h | ||
| kernel_emission.h | ||
| kernel_film.h | ||
| kernel_globals.h | ||
| kernel_jitter.h | ||
| kernel_light.h | ||
| kernel_math.h | ||
| kernel_montecarlo.h | ||
| kernel_passes.h | ||
| kernel_path_branched.h | ||
| kernel_path_common.h | ||
| kernel_path_state.h | ||
| kernel_path_surface.h | ||
| kernel_path_volume.h | ||
| kernel_path.h | ||
| kernel_projection.h | ||
| kernel_queues.h | ||
| kernel_random.h | ||
| kernel_shader.h | ||
| kernel_shadow.h | ||
| kernel_subsurface.h | ||
| kernel_textures.h | ||
| kernel_types.h | ||
| kernel_volume.h | ||
| kernel_work_stealing.h | ||
| kernel.h | ||