forked from bartvdbraak/blender
7f4479da42
This commit contains all the work related on the AMD megakernel split work which was mainly done by Varun Sundar, George Kyriazis and Lenny Wang, plus some help from Sergey Sharybin, Martijn Berger, Thomas Dinges and likely someone else which we're forgetting to mention. Currently only AMD cards are enabled for the new split kernel, but it is possible to force split opencl kernel to be used by setting the following environment variable: CYCLES_OPENCL_SPLIT_KERNEL_TEST=1. Not all the features are supported yet, and that being said no motion blur, camera blur, SSS and volumetrics for now. Also transparent shadows are disabled on AMD device because of some compiler bug. This kernel is also only implements regular path tracing and supporting branched one will take a bit. Branched path tracing is exposed to the interface still, which is a bit misleading and will be hidden there soon. More feature will be enabled once they're ported to the split kernel and tested. Neither regular CPU nor CUDA has any difference, they're generating the same exact code, which means no regressions/improvements there. Based on the research paper: https://research.nvidia.com/sites/default/files/publications/laine2013hpg_paper.pdf Here's the documentation: https://docs.google.com/document/d/1LuXW-CV-sVJkQaEGZlMJ86jZ8FmoPfecaMdR-oiWbUY/edit Design discussion of the patch: https://developer.blender.org/T44197 Differential Revision: https://developer.blender.org/D1200
173 lines
5.2 KiB
C
173 lines
5.2 KiB
C
/*
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* Copyright 2011-2013 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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CCL_NAMESPACE_BEGIN
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ccl_device_inline void path_state_init(KernelGlobals *kg, ccl_addr_space PathState *state, ccl_addr_space RNG *rng, int sample, ccl_addr_space Ray *ray)
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{
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state->flag = PATH_RAY_CAMERA|PATH_RAY_MIS_SKIP;
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state->rng_offset = PRNG_BASE_NUM;
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state->sample = sample;
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state->num_samples = kernel_data.integrator.aa_samples;
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state->bounce = 0;
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state->diffuse_bounce = 0;
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state->glossy_bounce = 0;
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state->transmission_bounce = 0;
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state->transparent_bounce = 0;
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state->min_ray_pdf = FLT_MAX;
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state->ray_pdf = 0.0f;
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#ifdef __LAMP_MIS__
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state->ray_t = 0.0f;
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#endif
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#ifdef __VOLUME__
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state->volume_bounce = 0;
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if(kernel_data.integrator.use_volumes) {
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/* initialize volume stack with volume we are inside of */
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kernel_volume_stack_init(kg, ray, state->volume_stack);
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/* seed RNG for cases where we can't use stratified samples */
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state->rng_congruential = lcg_init(*rng + sample*0x51633e2d);
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}
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else {
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state->volume_stack[0].shader = SHADER_NONE;
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}
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#endif
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}
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ccl_device_inline void path_state_next(KernelGlobals *kg, ccl_addr_space PathState *state, int label)
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{
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/* ray through transparent keeps same flags from previous ray and is
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* not counted as a regular bounce, transparent has separate max */
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if(label & LABEL_TRANSPARENT) {
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state->flag |= PATH_RAY_TRANSPARENT;
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state->transparent_bounce++;
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/* don't increase random number generator offset here, to avoid some
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* unwanted patterns, see path_state_rng_1D_for_decision */
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if(!kernel_data.integrator.transparent_shadows)
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state->flag |= PATH_RAY_MIS_SKIP;
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return;
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}
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state->bounce++;
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#ifdef __VOLUME__
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if(label & LABEL_VOLUME_SCATTER) {
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/* volume scatter */
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state->flag |= PATH_RAY_VOLUME_SCATTER;
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state->flag &= ~(PATH_RAY_REFLECT|PATH_RAY_TRANSMIT|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT|PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
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state->volume_bounce++;
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}
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else
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#endif
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{
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/* surface reflection/transmission */
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if(label & LABEL_REFLECT) {
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state->flag |= PATH_RAY_REFLECT;
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state->flag &= ~(PATH_RAY_TRANSMIT|PATH_RAY_VOLUME_SCATTER|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
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if(label & LABEL_DIFFUSE)
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state->diffuse_bounce++;
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else
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state->glossy_bounce++;
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}
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else {
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kernel_assert(label & LABEL_TRANSMIT);
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state->flag |= PATH_RAY_TRANSMIT;
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state->flag &= ~(PATH_RAY_REFLECT|PATH_RAY_VOLUME_SCATTER|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
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state->transmission_bounce++;
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}
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/* diffuse/glossy/singular */
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if(label & LABEL_DIFFUSE) {
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state->flag |= PATH_RAY_DIFFUSE|PATH_RAY_DIFFUSE_ANCESTOR;
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state->flag &= ~(PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
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}
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else if(label & LABEL_GLOSSY) {
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state->flag |= PATH_RAY_GLOSSY;
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state->flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
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}
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else {
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kernel_assert(label & LABEL_SINGULAR);
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state->flag |= PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP;
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state->flag &= ~PATH_RAY_DIFFUSE;
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}
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}
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/* random number generator next bounce */
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state->rng_offset += PRNG_BOUNCE_NUM;
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}
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ccl_device_inline uint path_state_ray_visibility(KernelGlobals *kg, PathState *state)
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{
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uint flag = state->flag & PATH_RAY_ALL_VISIBILITY;
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/* for visibility, diffuse/glossy are for reflection only */
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if(flag & PATH_RAY_TRANSMIT)
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flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY);
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/* todo: this is not supported as its own ray visibility yet */
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if(state->flag & PATH_RAY_VOLUME_SCATTER)
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flag |= PATH_RAY_DIFFUSE;
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/* for camera visibility, use render layer flags */
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if(flag & PATH_RAY_CAMERA)
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flag |= kernel_data.integrator.layer_flag;
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return flag;
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}
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ccl_device_inline float path_state_terminate_probability(KernelGlobals *kg, ccl_addr_space PathState *state, const float3 throughput)
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{
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if(state->flag & PATH_RAY_TRANSPARENT) {
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/* transparent rays treated separately */
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if(state->transparent_bounce >= kernel_data.integrator.transparent_max_bounce)
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return 0.0f;
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else if(state->transparent_bounce <= kernel_data.integrator.transparent_min_bounce)
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return 1.0f;
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}
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else {
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/* other rays */
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if((state->bounce >= kernel_data.integrator.max_bounce) ||
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(state->diffuse_bounce >= kernel_data.integrator.max_diffuse_bounce) ||
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(state->glossy_bounce >= kernel_data.integrator.max_glossy_bounce) ||
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#ifdef __VOLUME__
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(state->volume_bounce >= kernel_data.integrator.max_volume_bounce) ||
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#endif
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(state->transmission_bounce >= kernel_data.integrator.max_transmission_bounce))
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{
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return 0.0f;
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}
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else if(state->bounce <= kernel_data.integrator.min_bounce) {
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return 1.0f;
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}
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}
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/* probalistic termination */
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return average(throughput); /* todo: try using max here */
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}
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CCL_NAMESPACE_END
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