forked from bartvdbraak/blender
83e73a2100
This commit changes the way how we pass bounce information to the Light Path node. Instead of manualy copying the bounces into ShaderData, we now directly pass PathState. This reduces the arguments that we need to pass around and also makes it easier to extend the feature. This commit also exposes the Transmission Bounce Depth to the Light Path node. It works similar to the Transparent Depth Output: Replace a Transmission lightpath after X bounces with another shader, e.g a Diffuse one. This can be used to avoid black surfaces, due to low amount of max bounces. Reviewed by Sergey and Brecht, thanks for some hlp with this. I tested compilation and usage on CPU (SVM and OSL), CUDA, OpenCL Split and Mega kernel. Hopefully this covers all devices. :)
310 lines
9.3 KiB
C
310 lines
9.3 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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#if defined(__BRANCHED_PATH__) || defined(__SUBSURFACE__)
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/* branched path tracing: connect path directly to position on one or more lights and add it to L */
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ccl_device void kernel_branched_path_surface_connect_light(KernelGlobals *kg, RNG *rng,
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ShaderData *sd, PathState *state, float3 throughput, float num_samples_adjust, PathRadiance *L, bool sample_all_lights)
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{
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#ifdef __EMISSION__
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/* sample illumination from lights to find path contribution */
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if(!(ccl_fetch(sd, flag) & SD_BSDF_HAS_EVAL))
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return;
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Ray light_ray;
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BsdfEval L_light;
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bool is_lamp;
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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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if(sample_all_lights) {
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/* lamp sampling */
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for(int i = 0; i < kernel_data.integrator.num_all_lights; i++) {
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if(UNLIKELY(light_select_reached_max_bounces(kg, i, state->bounce)))
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continue;
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int num_samples = ceil_to_int(num_samples_adjust*light_select_num_samples(kg, i));
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float num_samples_inv = num_samples_adjust/(num_samples*kernel_data.integrator.num_all_lights);
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RNG lamp_rng = cmj_hash(*rng, i);
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if(kernel_data.integrator.pdf_triangles != 0.0f)
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num_samples_inv *= 0.5f;
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for(int j = 0; j < num_samples; j++) {
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float light_u, light_v;
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path_branched_rng_2D(kg, &lamp_rng, state, j, num_samples, PRNG_LIGHT_U, &light_u, &light_v);
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LightSample ls;
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lamp_light_sample(kg, i, light_u, light_v, ccl_fetch(sd, P), &ls);
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if(direct_emission(kg, sd, &ls, state, &light_ray, &L_light, &is_lamp)) {
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/* trace shadow ray */
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float3 shadow;
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if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
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/* accumulate */
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path_radiance_accum_light(L, throughput*num_samples_inv, &L_light, shadow, num_samples_inv, state->bounce, is_lamp);
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}
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}
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}
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}
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/* mesh light sampling */
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if(kernel_data.integrator.pdf_triangles != 0.0f) {
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int num_samples = ceil_to_int(num_samples_adjust*kernel_data.integrator.mesh_light_samples);
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float num_samples_inv = num_samples_adjust/num_samples;
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if(kernel_data.integrator.num_all_lights)
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num_samples_inv *= 0.5f;
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for(int j = 0; j < num_samples; j++) {
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float light_t = path_branched_rng_1D(kg, rng, state, j, num_samples, PRNG_LIGHT);
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float light_u, light_v;
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path_branched_rng_2D(kg, rng, state, j, num_samples, PRNG_LIGHT_U, &light_u, &light_v);
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/* only sample triangle lights */
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if(kernel_data.integrator.num_all_lights)
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light_t = 0.5f*light_t;
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LightSample ls;
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light_sample(kg, light_t, light_u, light_v, ccl_fetch(sd, time), ccl_fetch(sd, P), state->bounce, &ls);
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if(direct_emission(kg, sd, &ls, state, &light_ray, &L_light, &is_lamp)) {
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/* trace shadow ray */
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float3 shadow;
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if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
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/* accumulate */
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path_radiance_accum_light(L, throughput*num_samples_inv, &L_light, shadow, num_samples_inv, state->bounce, is_lamp);
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}
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}
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}
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}
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}
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else {
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/* sample one light at random */
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float light_t = path_state_rng_1D(kg, rng, state, PRNG_LIGHT);
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float light_u, light_v;
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path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v);
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LightSample ls;
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light_sample(kg, light_t, light_u, light_v, ccl_fetch(sd, time), ccl_fetch(sd, P), state->bounce, &ls);
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/* sample random light */
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if(direct_emission(kg, sd, &ls, state, &light_ray, &L_light, &is_lamp)) {
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/* trace shadow ray */
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float3 shadow;
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if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
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/* accumulate */
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path_radiance_accum_light(L, throughput*num_samples_adjust, &L_light, shadow, num_samples_adjust, state->bounce, is_lamp);
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}
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}
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}
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#endif
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}
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/* branched path tracing: bounce off or through surface to with new direction stored in ray */
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ccl_device bool kernel_branched_path_surface_bounce(KernelGlobals *kg, RNG *rng,
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ShaderData *sd, const ShaderClosure *sc, int sample, int num_samples,
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float3 *throughput, PathState *state, PathRadiance *L, Ray *ray)
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{
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/* sample BSDF */
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float bsdf_pdf;
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BsdfEval bsdf_eval;
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float3 bsdf_omega_in;
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differential3 bsdf_domega_in;
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float bsdf_u, bsdf_v;
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path_branched_rng_2D(kg, rng, state, sample, num_samples, PRNG_BSDF_U, &bsdf_u, &bsdf_v);
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int label;
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label = shader_bsdf_sample_closure(kg, sd, sc, bsdf_u, bsdf_v, &bsdf_eval,
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&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
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if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
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return false;
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/* modify throughput */
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path_radiance_bsdf_bounce(L, throughput, &bsdf_eval, bsdf_pdf, state->bounce, label);
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/* modify path state */
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path_state_next(kg, state, label);
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/* setup ray */
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ray->P = ray_offset(ccl_fetch(sd, P), (label & LABEL_TRANSMIT)? -ccl_fetch(sd, Ng): ccl_fetch(sd, Ng));
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ray->D = normalize(bsdf_omega_in);
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ray->t = FLT_MAX;
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#ifdef __RAY_DIFFERENTIALS__
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ray->dP = ccl_fetch(sd, dP);
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ray->dD = bsdf_domega_in;
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#endif
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#ifdef __OBJECT_MOTION__
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ray->time = ccl_fetch(sd, time);
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#endif
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#ifdef __VOLUME__
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/* enter/exit volume */
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if(label & LABEL_TRANSMIT)
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kernel_volume_stack_enter_exit(kg, sd, state->volume_stack);
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#endif
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/* branch RNG state */
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path_state_branch(state, sample, num_samples);
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/* set MIS state */
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state->min_ray_pdf = fminf(bsdf_pdf, FLT_MAX);
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state->ray_pdf = bsdf_pdf;
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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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return true;
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}
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#endif
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#ifndef __SPLIT_KERNEL__
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/* path tracing: connect path directly to position on a light and add it to L */
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ccl_device_inline void kernel_path_surface_connect_light(KernelGlobals *kg, ccl_addr_space RNG *rng,
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ShaderData *sd, float3 throughput, ccl_addr_space PathState *state, PathRadiance *L)
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{
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#ifdef __EMISSION__
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if(!(kernel_data.integrator.use_direct_light && (ccl_fetch(sd, flag) & SD_BSDF_HAS_EVAL)))
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return;
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/* sample illumination from lights to find path contribution */
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float light_t = path_state_rng_1D(kg, rng, state, PRNG_LIGHT);
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float light_u, light_v;
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path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v);
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Ray light_ray;
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BsdfEval L_light;
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bool is_lamp;
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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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LightSample ls;
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light_sample(kg, light_t, light_u, light_v, ccl_fetch(sd, time), ccl_fetch(sd, P), state->bounce, &ls);
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if(direct_emission(kg, sd, &ls, state, &light_ray, &L_light, &is_lamp)) {
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/* trace shadow ray */
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float3 shadow;
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if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
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/* accumulate */
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path_radiance_accum_light(L, throughput, &L_light, shadow, 1.0f, state->bounce, is_lamp);
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}
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}
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#endif
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}
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#endif
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/* path tracing: bounce off or through surface to with new direction stored in ray */
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ccl_device_inline bool kernel_path_surface_bounce(KernelGlobals *kg, ccl_addr_space RNG *rng,
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ShaderData *sd, ccl_addr_space float3 *throughput, ccl_addr_space PathState *state, PathRadiance *L, ccl_addr_space Ray *ray)
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{
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/* no BSDF? we can stop here */
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if(ccl_fetch(sd, flag) & SD_BSDF) {
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/* sample BSDF */
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float bsdf_pdf;
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BsdfEval bsdf_eval;
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float3 bsdf_omega_in;
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differential3 bsdf_domega_in;
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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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int label;
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label = shader_bsdf_sample(kg, sd, bsdf_u, bsdf_v, &bsdf_eval,
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&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
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if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
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return false;
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/* modify throughput */
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path_radiance_bsdf_bounce(L, throughput, &bsdf_eval, bsdf_pdf, state->bounce, label);
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/* set labels */
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if(!(label & LABEL_TRANSPARENT)) {
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state->ray_pdf = bsdf_pdf;
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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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state->min_ray_pdf = fminf(bsdf_pdf, state->min_ray_pdf);
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}
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/* update path state */
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path_state_next(kg, state, label);
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/* setup ray */
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ray->P = ray_offset(ccl_fetch(sd, P), (label & LABEL_TRANSMIT)? -ccl_fetch(sd, Ng): ccl_fetch(sd, Ng));
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ray->D = normalize(bsdf_omega_in);
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if(state->bounce == 0)
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ray->t -= ccl_fetch(sd, ray_length); /* clipping works through transparent */
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else
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ray->t = FLT_MAX;
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#ifdef __RAY_DIFFERENTIALS__
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ray->dP = ccl_fetch(sd, dP);
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ray->dD = bsdf_domega_in;
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#endif
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#ifdef __VOLUME__
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/* enter/exit volume */
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if(label & LABEL_TRANSMIT)
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kernel_volume_stack_enter_exit(kg, sd, state->volume_stack);
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#endif
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return true;
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}
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#ifdef __VOLUME__
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else if(ccl_fetch(sd, flag) & SD_HAS_ONLY_VOLUME) {
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/* no surface shader but have a volume shader? act transparent */
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/* update path state, count as transparent */
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path_state_next(kg, state, LABEL_TRANSPARENT);
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if(state->bounce == 0)
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ray->t -= ccl_fetch(sd, ray_length); /* clipping works through transparent */
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else
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ray->t = FLT_MAX;
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/* setup ray position, direction stays unchanged */
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ray->P = ray_offset(ccl_fetch(sd, P), -ccl_fetch(sd, Ng));
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#ifdef __RAY_DIFFERENTIALS__
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ray->dP = ccl_fetch(sd, dP);
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#endif
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/* enter/exit volume */
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kernel_volume_stack_enter_exit(kg, sd, state->volume_stack);
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return true;
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}
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#endif
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else {
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/* no bsdf or volume? */
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return false;
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}
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}
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CCL_NAMESPACE_END
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