8bca34fe32
This commit introduces a SSS-oriented intersection structure which is replacing old logic of having separate arrays for just intersections and shader data and encapsulates all the data needed for SSS evaluation. This giver a huge stack memory saving on GPU. In own experiments it gave 25% memory usage reduction on GTX560Ti (722MB vs. 946MB). Unfortunately, this gave some performance loss of 20% which only happens on GPU. This is perhaps due to different memory access pattern. Will be solved in the future, hopefully. Famous saying: won in memory - lost in time (which is also valid in other way around).
724 lines
22 KiB
C
724 lines
22 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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#ifdef __OSL__
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#include "osl_shader.h"
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#endif
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#include "kernel_random.h"
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#include "kernel_projection.h"
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#include "kernel_montecarlo.h"
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#include "kernel_differential.h"
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#include "kernel_camera.h"
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#include "geom/geom.h"
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#include "kernel_accumulate.h"
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#include "kernel_shader.h"
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#include "kernel_light.h"
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#include "kernel_passes.h"
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#ifdef __SUBSURFACE__
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#include "kernel_subsurface.h"
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#endif
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#ifdef __VOLUME__
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#include "kernel_volume.h"
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#endif
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#include "kernel_path_state.h"
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#include "kernel_shadow.h"
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#include "kernel_emission.h"
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#include "kernel_path_common.h"
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#include "kernel_path_surface.h"
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#include "kernel_path_volume.h"
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#ifdef __KERNEL_DEBUG__
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#include "kernel_debug.h"
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#endif
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CCL_NAMESPACE_BEGIN
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ccl_device void kernel_path_indirect(KernelGlobals *kg, RNG *rng, Ray ray,
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float3 throughput, int num_samples, PathState state, PathRadiance *L)
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{
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/* path iteration */
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for(;;) {
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/* intersect scene */
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Intersection isect;
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uint visibility = path_state_ray_visibility(kg, &state);
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bool hit = scene_intersect(kg, &ray, visibility, &isect, NULL, 0.0f, 0.0f);
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#ifdef __LAMP_MIS__
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if(kernel_data.integrator.use_lamp_mis && !(state.flag & PATH_RAY_CAMERA)) {
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/* ray starting from previous non-transparent bounce */
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Ray light_ray;
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light_ray.P = ray.P - state.ray_t*ray.D;
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state.ray_t += isect.t;
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light_ray.D = ray.D;
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light_ray.t = state.ray_t;
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light_ray.time = ray.time;
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light_ray.dD = ray.dD;
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light_ray.dP = ray.dP;
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/* intersect with lamp */
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float3 emission;
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if(indirect_lamp_emission(kg, &state, &light_ray, &emission))
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path_radiance_accum_emission(L, throughput, emission, state.bounce);
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}
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#endif
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#ifdef __VOLUME__
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/* volume attenuation, emission, scatter */
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if(state.volume_stack[0].shader != SHADER_NONE) {
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Ray volume_ray = ray;
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volume_ray.t = (hit)? isect.t: FLT_MAX;
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bool heterogeneous = volume_stack_is_heterogeneous(kg, state.volume_stack);
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#ifdef __VOLUME_DECOUPLED__
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int sampling_method = volume_stack_sampling_method(kg, state.volume_stack);
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bool decoupled = kernel_volume_use_decoupled(kg, heterogeneous, false, sampling_method);
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if(decoupled) {
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/* cache steps along volume for repeated sampling */
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VolumeSegment volume_segment;
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ShaderData volume_sd;
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shader_setup_from_volume(kg, &volume_sd, &volume_ray, state.bounce, state.transparent_bounce);
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kernel_volume_decoupled_record(kg, &state,
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&volume_ray, &volume_sd, &volume_segment, heterogeneous);
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volume_segment.sampling_method = sampling_method;
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/* emission */
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if(volume_segment.closure_flag & SD_EMISSION)
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path_radiance_accum_emission(L, throughput, volume_segment.accum_emission, state.bounce);
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/* scattering */
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VolumeIntegrateResult result = VOLUME_PATH_ATTENUATED;
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if(volume_segment.closure_flag & SD_SCATTER) {
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bool all = kernel_data.integrator.sample_all_lights_indirect;
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/* direct light sampling */
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kernel_branched_path_volume_connect_light(kg, rng, &volume_sd,
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throughput, &state, L, all, &volume_ray, &volume_segment);
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/* indirect sample. if we use distance sampling and take just
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* one sample for direct and indirect light, we could share
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* this computation, but makes code a bit complex */
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float rphase = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_PHASE);
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float rscatter = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_SCATTER_DISTANCE);
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result = kernel_volume_decoupled_scatter(kg,
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&state, &volume_ray, &volume_sd, &throughput,
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rphase, rscatter, &volume_segment, NULL, true);
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}
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/* free cached steps */
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kernel_volume_decoupled_free(kg, &volume_segment);
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if(result == VOLUME_PATH_SCATTERED) {
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if(kernel_path_volume_bounce(kg, rng, &volume_sd, &throughput, &state, L, &ray))
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continue;
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else
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break;
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}
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else {
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throughput *= volume_segment.accum_transmittance;
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}
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}
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else
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#endif
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{
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/* integrate along volume segment with distance sampling */
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ShaderData volume_sd;
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VolumeIntegrateResult result = kernel_volume_integrate(
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kg, &state, &volume_sd, &volume_ray, L, &throughput, rng, heterogeneous);
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#ifdef __VOLUME_SCATTER__
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if(result == VOLUME_PATH_SCATTERED) {
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/* direct lighting */
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kernel_path_volume_connect_light(kg, rng, &volume_sd, throughput, &state, L);
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/* indirect light bounce */
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if(kernel_path_volume_bounce(kg, rng, &volume_sd, &throughput, &state, L, &ray))
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continue;
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else
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break;
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}
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#endif
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}
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}
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#endif
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if(!hit) {
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#ifdef __BACKGROUND__
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/* sample background shader */
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float3 L_background = indirect_background(kg, &state, &ray);
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path_radiance_accum_background(L, throughput, L_background, state.bounce);
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#endif
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break;
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}
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/* setup shading */
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ShaderData sd;
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shader_setup_from_ray(kg, &sd, &isect, &ray, state.bounce, state.transparent_bounce);
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float rbsdf = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_BSDF);
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shader_eval_surface(kg, &sd, rbsdf, state.flag, SHADER_CONTEXT_INDIRECT);
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#ifdef __BRANCHED_PATH__
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shader_merge_closures(&sd);
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#endif
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/* blurring of bsdf after bounces, for rays that have a small likelihood
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* of following this particular path (diffuse, rough glossy) */
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if(kernel_data.integrator.filter_glossy != FLT_MAX) {
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float blur_pdf = kernel_data.integrator.filter_glossy*state.min_ray_pdf;
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if(blur_pdf < 1.0f) {
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float blur_roughness = sqrtf(1.0f - blur_pdf)*0.5f;
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shader_bsdf_blur(kg, &sd, blur_roughness);
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}
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}
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#ifdef __EMISSION__
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/* emission */
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if(sd.flag & SD_EMISSION) {
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float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, state.ray_pdf);
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path_radiance_accum_emission(L, throughput, emission, state.bounce);
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}
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#endif
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/* path termination. this is a strange place to put the termination, it's
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* mainly due to the mixed in MIS that we use. gives too many unneeded
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* shader evaluations, only need emission if we are going to terminate */
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float probability = path_state_terminate_probability(kg, &state, throughput*num_samples);
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if(probability == 0.0f) {
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break;
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}
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else if(probability != 1.0f) {
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float terminate = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_TERMINATE);
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if(terminate >= probability)
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break;
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throughput /= probability;
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}
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#ifdef __AO__
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/* ambient occlusion */
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if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
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float bsdf_u, bsdf_v;
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path_state_rng_2D(kg, rng, &state, PRNG_BSDF_U, &bsdf_u, &bsdf_v);
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float ao_factor = kernel_data.background.ao_factor;
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float3 ao_N;
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float3 ao_bsdf = shader_bsdf_ao(kg, &sd, ao_factor, &ao_N);
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float3 ao_D;
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float ao_pdf;
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float3 ao_alpha = make_float3(0.0f, 0.0f, 0.0f);
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sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
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if(dot(sd.Ng, ao_D) > 0.0f && ao_pdf != 0.0f) {
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Ray light_ray;
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float3 ao_shadow;
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light_ray.P = ray_offset(sd.P, sd.Ng);
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light_ray.D = ao_D;
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light_ray.t = kernel_data.background.ao_distance;
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#ifdef __OBJECT_MOTION__
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light_ray.time = sd.time;
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#endif
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light_ray.dP = sd.dP;
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light_ray.dD = differential3_zero();
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if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow))
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path_radiance_accum_ao(L, throughput, ao_alpha, ao_bsdf, ao_shadow, state.bounce);
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}
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}
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#endif
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#ifdef __SUBSURFACE__
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/* bssrdf scatter to a different location on the same object, replacing
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* the closures with a diffuse BSDF */
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if(sd.flag & SD_BSSRDF) {
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float bssrdf_probability;
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ShaderClosure *sc = subsurface_scatter_pick_closure(kg, &sd, &bssrdf_probability);
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/* modify throughput for picking bssrdf or bsdf */
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throughput *= bssrdf_probability;
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/* do bssrdf scatter step if we picked a bssrdf closure */
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if(sc) {
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uint lcg_state = lcg_state_init(rng, &state, 0x68bc21eb);
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float bssrdf_u, bssrdf_v;
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path_state_rng_2D(kg, rng, &state, PRNG_BSDF_U, &bssrdf_u, &bssrdf_v);
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subsurface_scatter_step(kg, &sd, state.flag, sc, &lcg_state, bssrdf_u, bssrdf_v, false);
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}
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}
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#endif
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#if defined(__EMISSION__) && defined(__BRANCHED_PATH__)
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if(kernel_data.integrator.use_direct_light) {
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bool all = kernel_data.integrator.sample_all_lights_indirect;
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kernel_branched_path_surface_connect_light(kg, rng, &sd, &state, throughput, 1.0f, L, all);
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}
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#endif
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if(!kernel_path_surface_bounce(kg, rng, &sd, &throughput, &state, L, &ray))
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break;
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}
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}
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ccl_device void kernel_path_ao(KernelGlobals *kg, ShaderData *sd, PathRadiance *L, PathState *state, RNG *rng, float3 throughput)
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{
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/* todo: solve correlation */
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float bsdf_u, bsdf_v;
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path_state_rng_2D(kg, rng, state, PRNG_BSDF_U, &bsdf_u, &bsdf_v);
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float ao_factor = kernel_data.background.ao_factor;
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float3 ao_N;
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float3 ao_bsdf = shader_bsdf_ao(kg, sd, ao_factor, &ao_N);
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float3 ao_D;
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float ao_pdf;
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float3 ao_alpha = shader_bsdf_alpha(kg, sd);
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sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
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if(dot(ccl_fetch(sd, Ng), ao_D) > 0.0f && ao_pdf != 0.0f) {
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Ray light_ray;
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float3 ao_shadow;
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light_ray.P = ray_offset(ccl_fetch(sd, P), ccl_fetch(sd, Ng));
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light_ray.D = ao_D;
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light_ray.t = kernel_data.background.ao_distance;
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#ifdef __OBJECT_MOTION__
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light_ray.time = ccl_fetch(sd, time);
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#endif
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light_ray.dP = ccl_fetch(sd, dP);
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light_ray.dD = differential3_zero();
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if(!shadow_blocked(kg, state, &light_ray, &ao_shadow))
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path_radiance_accum_ao(L, throughput, ao_alpha, ao_bsdf, ao_shadow, state->bounce);
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}
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}
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#ifdef __SUBSURFACE__
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ccl_device bool kernel_path_subsurface_scatter(KernelGlobals *kg, ShaderData *sd, PathRadiance *L, PathState *state, RNG *rng, Ray *ray, float3 *throughput)
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{
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float bssrdf_probability;
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ShaderClosure *sc = subsurface_scatter_pick_closure(kg, sd, &bssrdf_probability);
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/* modify throughput for picking bssrdf or bsdf */
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*throughput *= bssrdf_probability;
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/* do bssrdf scatter step if we picked a bssrdf closure */
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if(sc) {
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uint lcg_state = lcg_state_init(rng, state, 0x68bc21eb);
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SubsurfaceIntersection ss_isect;
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float bssrdf_u, bssrdf_v;
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path_state_rng_2D(kg, rng, state, PRNG_BSDF_U, &bssrdf_u, &bssrdf_v);
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int num_hits = subsurface_scatter_multi_intersect(kg,
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&ss_isect,
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sd,
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sc,
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&lcg_state,
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bssrdf_u, bssrdf_v,
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false);
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#ifdef __VOLUME__
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Ray volume_ray = *ray;
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bool need_update_volume_stack = kernel_data.integrator.use_volumes &&
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ccl_fetch(sd, flag) & SD_OBJECT_INTERSECTS_VOLUME;
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#endif
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/* compute lighting with the BSDF closure */
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for(int hit = 0; hit < num_hits; hit++) {
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/* NOTE: We reuse the existing ShaderData, we assume the path
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* integration loop stops when this function returns true.
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*/
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subsurface_scatter_multi_setup(kg,
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&ss_isect,
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hit,
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sd,
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state->flag,
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sc,
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false);
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float3 tp = *throughput;
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PathState hit_state = *state;
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Ray hit_ray = *ray;
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hit_state.rng_offset += PRNG_BOUNCE_NUM;
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kernel_path_surface_connect_light(kg, rng, sd, tp, state, L);
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if(kernel_path_surface_bounce(kg, rng, sd, &tp, &hit_state, L, &hit_ray)) {
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#ifdef __LAMP_MIS__
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hit_state.ray_t = 0.0f;
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#endif
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#ifdef __VOLUME__
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if(need_update_volume_stack) {
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/* Setup ray from previous surface point to the new one. */
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volume_ray.D = normalize_len(hit_ray.P - volume_ray.P,
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&volume_ray.t);
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kernel_volume_stack_update_for_subsurface(
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kg,
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&volume_ray,
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hit_state.volume_stack);
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/* Move volume ray forward. */
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volume_ray.P = hit_ray.P;
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}
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#endif
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kernel_path_indirect(kg, rng, hit_ray, tp, state->num_samples, hit_state, L);
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/* for render passes, sum and reset indirect light pass variables
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* for the next samples */
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path_radiance_sum_indirect(L);
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path_radiance_reset_indirect(L);
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}
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}
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return true;
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}
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return false;
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}
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#endif
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ccl_device float4 kernel_path_integrate(KernelGlobals *kg, RNG *rng, int sample, Ray ray, ccl_global float *buffer)
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{
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/* initialize */
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PathRadiance L;
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float3 throughput = make_float3(1.0f, 1.0f, 1.0f);
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float L_transparent = 0.0f;
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path_radiance_init(&L, kernel_data.film.use_light_pass);
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PathState state;
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path_state_init(kg, &state, rng, sample, &ray);
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#ifdef __KERNEL_DEBUG__
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DebugData debug_data;
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debug_data_init(&debug_data);
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#endif
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/* path iteration */
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for(;;) {
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/* intersect scene */
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Intersection isect;
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uint visibility = path_state_ray_visibility(kg, &state);
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#ifdef __HAIR__
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float difl = 0.0f, extmax = 0.0f;
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uint lcg_state = 0;
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if(kernel_data.bvh.have_curves) {
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if((kernel_data.cam.resolution == 1) && (state.flag & PATH_RAY_CAMERA)) {
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float3 pixdiff = ray.dD.dx + ray.dD.dy;
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/*pixdiff = pixdiff - dot(pixdiff, ray.D)*ray.D;*/
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difl = kernel_data.curve.minimum_width * len(pixdiff) * 0.5f;
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}
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extmax = kernel_data.curve.maximum_width;
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lcg_state = lcg_state_init(rng, &state, 0x51633e2d);
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}
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bool hit = scene_intersect(kg, &ray, visibility, &isect, &lcg_state, difl, extmax);
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#else
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bool hit = scene_intersect(kg, &ray, visibility, &isect, NULL, 0.0f, 0.0f);
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#endif
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#ifdef __KERNEL_DEBUG__
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if(state.flag & PATH_RAY_CAMERA) {
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debug_data.num_bvh_traversal_steps += isect.num_traversal_steps;
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debug_data.num_bvh_traversed_instances += isect.num_traversed_instances;
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}
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debug_data.num_ray_bounces++;
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#endif
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|
#ifdef __LAMP_MIS__
|
|
if(kernel_data.integrator.use_lamp_mis && !(state.flag & PATH_RAY_CAMERA)) {
|
|
/* ray starting from previous non-transparent bounce */
|
|
Ray light_ray;
|
|
|
|
light_ray.P = ray.P - state.ray_t*ray.D;
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|
state.ray_t += isect.t;
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|
light_ray.D = ray.D;
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|
light_ray.t = state.ray_t;
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|
light_ray.time = ray.time;
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|
light_ray.dD = ray.dD;
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|
light_ray.dP = ray.dP;
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|
|
|
/* intersect with lamp */
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|
float3 emission;
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|
|
|
if(indirect_lamp_emission(kg, &state, &light_ray, &emission))
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|
path_radiance_accum_emission(&L, throughput, emission, state.bounce);
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|
}
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|
#endif
|
|
|
|
#ifdef __VOLUME__
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|
/* volume attenuation, emission, scatter */
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|
if(state.volume_stack[0].shader != SHADER_NONE) {
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|
Ray volume_ray = ray;
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|
volume_ray.t = (hit)? isect.t: FLT_MAX;
|
|
|
|
bool heterogeneous = volume_stack_is_heterogeneous(kg, state.volume_stack);
|
|
|
|
#ifdef __VOLUME_DECOUPLED__
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|
int sampling_method = volume_stack_sampling_method(kg, state.volume_stack);
|
|
bool decoupled = kernel_volume_use_decoupled(kg, heterogeneous, true, sampling_method);
|
|
|
|
if(decoupled) {
|
|
/* cache steps along volume for repeated sampling */
|
|
VolumeSegment volume_segment;
|
|
ShaderData volume_sd;
|
|
|
|
shader_setup_from_volume(kg, &volume_sd, &volume_ray, state.bounce, state.transparent_bounce);
|
|
kernel_volume_decoupled_record(kg, &state,
|
|
&volume_ray, &volume_sd, &volume_segment, heterogeneous);
|
|
|
|
volume_segment.sampling_method = sampling_method;
|
|
|
|
/* emission */
|
|
if(volume_segment.closure_flag & SD_EMISSION)
|
|
path_radiance_accum_emission(&L, throughput, volume_segment.accum_emission, state.bounce);
|
|
|
|
/* scattering */
|
|
VolumeIntegrateResult result = VOLUME_PATH_ATTENUATED;
|
|
|
|
if(volume_segment.closure_flag & SD_SCATTER) {
|
|
bool all = false;
|
|
|
|
/* direct light sampling */
|
|
kernel_branched_path_volume_connect_light(kg, rng, &volume_sd,
|
|
throughput, &state, &L, all, &volume_ray, &volume_segment);
|
|
|
|
/* indirect sample. if we use distance sampling and take just
|
|
* one sample for direct and indirect light, we could share
|
|
* this computation, but makes code a bit complex */
|
|
float rphase = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_PHASE);
|
|
float rscatter = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_SCATTER_DISTANCE);
|
|
|
|
result = kernel_volume_decoupled_scatter(kg,
|
|
&state, &volume_ray, &volume_sd, &throughput,
|
|
rphase, rscatter, &volume_segment, NULL, true);
|
|
}
|
|
|
|
/* free cached steps */
|
|
kernel_volume_decoupled_free(kg, &volume_segment);
|
|
|
|
if(result == VOLUME_PATH_SCATTERED) {
|
|
if(kernel_path_volume_bounce(kg, rng, &volume_sd, &throughput, &state, &L, &ray))
|
|
continue;
|
|
else
|
|
break;
|
|
}
|
|
else {
|
|
throughput *= volume_segment.accum_transmittance;
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
/* integrate along volume segment with distance sampling */
|
|
ShaderData volume_sd;
|
|
VolumeIntegrateResult result = kernel_volume_integrate(
|
|
kg, &state, &volume_sd, &volume_ray, &L, &throughput, rng, heterogeneous);
|
|
|
|
#ifdef __VOLUME_SCATTER__
|
|
if(result == VOLUME_PATH_SCATTERED) {
|
|
/* direct lighting */
|
|
kernel_path_volume_connect_light(kg, rng, &volume_sd, throughput, &state, &L);
|
|
|
|
/* indirect light bounce */
|
|
if(kernel_path_volume_bounce(kg, rng, &volume_sd, &throughput, &state, &L, &ray))
|
|
continue;
|
|
else
|
|
break;
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if(!hit) {
|
|
/* eval background shader if nothing hit */
|
|
if(kernel_data.background.transparent && (state.flag & PATH_RAY_CAMERA)) {
|
|
L_transparent += average(throughput);
|
|
|
|
#ifdef __PASSES__
|
|
if(!(kernel_data.film.pass_flag & PASS_BACKGROUND))
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
#ifdef __BACKGROUND__
|
|
/* sample background shader */
|
|
float3 L_background = indirect_background(kg, &state, &ray);
|
|
path_radiance_accum_background(&L, throughput, L_background, state.bounce);
|
|
#endif
|
|
|
|
break;
|
|
}
|
|
|
|
/* setup shading */
|
|
ShaderData sd;
|
|
shader_setup_from_ray(kg, &sd, &isect, &ray, state.bounce, state.transparent_bounce);
|
|
float rbsdf = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_BSDF);
|
|
shader_eval_surface(kg, &sd, rbsdf, state.flag, SHADER_CONTEXT_MAIN);
|
|
|
|
/* holdout */
|
|
#ifdef __HOLDOUT__
|
|
if((sd.flag & (SD_HOLDOUT|SD_HOLDOUT_MASK)) && (state.flag & PATH_RAY_CAMERA)) {
|
|
if(kernel_data.background.transparent) {
|
|
float3 holdout_weight;
|
|
|
|
if(sd.flag & SD_HOLDOUT_MASK)
|
|
holdout_weight = make_float3(1.0f, 1.0f, 1.0f);
|
|
else
|
|
holdout_weight = shader_holdout_eval(kg, &sd);
|
|
|
|
/* any throughput is ok, should all be identical here */
|
|
L_transparent += average(holdout_weight*throughput);
|
|
}
|
|
|
|
if(sd.flag & SD_HOLDOUT_MASK)
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
/* holdout mask objects do not write data passes */
|
|
kernel_write_data_passes(kg, buffer, &L, &sd, sample, &state, throughput);
|
|
|
|
/* blurring of bsdf after bounces, for rays that have a small likelihood
|
|
* of following this particular path (diffuse, rough glossy) */
|
|
if(kernel_data.integrator.filter_glossy != FLT_MAX) {
|
|
float blur_pdf = kernel_data.integrator.filter_glossy*state.min_ray_pdf;
|
|
|
|
if(blur_pdf < 1.0f) {
|
|
float blur_roughness = sqrtf(1.0f - blur_pdf)*0.5f;
|
|
shader_bsdf_blur(kg, &sd, blur_roughness);
|
|
}
|
|
}
|
|
|
|
#ifdef __EMISSION__
|
|
/* emission */
|
|
if(sd.flag & SD_EMISSION) {
|
|
/* todo: is isect.t wrong here for transparent surfaces? */
|
|
float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, state.ray_pdf);
|
|
path_radiance_accum_emission(&L, throughput, emission, state.bounce);
|
|
}
|
|
#endif
|
|
|
|
/* path termination. this is a strange place to put the termination, it's
|
|
* mainly due to the mixed in MIS that we use. gives too many unneeded
|
|
* shader evaluations, only need emission if we are going to terminate */
|
|
float probability = path_state_terminate_probability(kg, &state, throughput);
|
|
|
|
if(probability == 0.0f) {
|
|
break;
|
|
}
|
|
else if(probability != 1.0f) {
|
|
float terminate = path_state_rng_1D_for_decision(kg, rng, &state, PRNG_TERMINATE);
|
|
|
|
if(terminate >= probability)
|
|
break;
|
|
|
|
throughput /= probability;
|
|
}
|
|
|
|
#ifdef __AO__
|
|
/* ambient occlusion */
|
|
if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
|
|
kernel_path_ao(kg, &sd, &L, &state, rng, throughput);
|
|
}
|
|
#endif
|
|
|
|
#ifdef __SUBSURFACE__
|
|
/* bssrdf scatter to a different location on the same object, replacing
|
|
* the closures with a diffuse BSDF */
|
|
if(sd.flag & SD_BSSRDF) {
|
|
if(kernel_path_subsurface_scatter(kg, &sd, &L, &state, rng, &ray, &throughput))
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
/* direct lighting */
|
|
kernel_path_surface_connect_light(kg, rng, &sd, throughput, &state, &L);
|
|
|
|
/* compute direct lighting and next bounce */
|
|
if(!kernel_path_surface_bounce(kg, rng, &sd, &throughput, &state, &L, &ray))
|
|
break;
|
|
}
|
|
|
|
float3 L_sum = path_radiance_clamp_and_sum(kg, &L);
|
|
|
|
kernel_write_light_passes(kg, buffer, &L, sample);
|
|
|
|
#ifdef __KERNEL_DEBUG__
|
|
kernel_write_debug_passes(kg, buffer, &state, &debug_data, sample);
|
|
#endif
|
|
|
|
return make_float4(L_sum.x, L_sum.y, L_sum.z, 1.0f - L_transparent);
|
|
}
|
|
|
|
ccl_device void kernel_path_trace(KernelGlobals *kg,
|
|
ccl_global float *buffer, ccl_global uint *rng_state,
|
|
int sample, int x, int y, int offset, int stride)
|
|
{
|
|
/* buffer offset */
|
|
int index = offset + x + y*stride;
|
|
int pass_stride = kernel_data.film.pass_stride;
|
|
|
|
rng_state += index;
|
|
buffer += index*pass_stride;
|
|
|
|
/* initialize random numbers and ray */
|
|
RNG rng;
|
|
Ray ray;
|
|
|
|
kernel_path_trace_setup(kg, rng_state, sample, x, y, &rng, &ray);
|
|
|
|
/* integrate */
|
|
float4 L;
|
|
|
|
if(ray.t != 0.0f)
|
|
L = kernel_path_integrate(kg, &rng, sample, ray, buffer);
|
|
else
|
|
L = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
|
|
|
|
/* accumulate result in output buffer */
|
|
kernel_write_pass_float4(buffer, sample, L);
|
|
|
|
path_rng_end(kg, rng_state, rng);
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|
|
|