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. :)
316 lines
9.1 KiB
C
316 lines
9.1 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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/* Direction Emission */
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ccl_device_noinline float3 direct_emissive_eval(KernelGlobals *kg,
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LightSample *ls, ccl_addr_space PathState *state, float3 I, differential3 dI, float t, float time
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#ifdef __SPLIT_KERNEL__
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,ShaderData *sd_input
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#endif
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)
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{
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/* setup shading at emitter */
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#ifdef __SPLIT_KERNEL__
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ShaderData *sd = sd_input;
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#else
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ShaderData sd_object;
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ShaderData *sd = &sd_object;
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#endif
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float3 eval;
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#ifdef __BACKGROUND_MIS__
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if(ls->type == LIGHT_BACKGROUND) {
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Ray ray;
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ray.D = ls->D;
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ray.P = ls->P;
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ray.t = 1.0f;
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#ifdef __OBJECT_MOTION__
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ray.time = time;
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#endif
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ray.dP = differential3_zero();
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ray.dD = dI;
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shader_setup_from_background(kg, sd, &ray);
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path_state_modify_bounce(state, true);
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eval = shader_eval_background(kg, sd, state, 0, SHADER_CONTEXT_EMISSION);
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path_state_modify_bounce(state, false);
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}
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else
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#endif
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{
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shader_setup_from_sample(kg, sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, ls->u, ls->v, t, time);
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ls->Ng = ccl_fetch(sd, Ng);
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/* no path flag, we're evaluating this for all closures. that's weak but
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* we'd have to do multiple evaluations otherwise */
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path_state_modify_bounce(state, true);
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shader_eval_surface(kg, sd, state, 0.0f, 0, SHADER_CONTEXT_EMISSION);
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path_state_modify_bounce(state, false);
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/* evaluate emissive closure */
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if(ccl_fetch(sd, flag) & SD_EMISSION)
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eval = shader_emissive_eval(kg, sd);
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else
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eval = make_float3(0.0f, 0.0f, 0.0f);
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}
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eval *= ls->eval_fac;
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return eval;
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}
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ccl_device_noinline bool direct_emission(KernelGlobals *kg, ShaderData *sd,
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LightSample *ls, ccl_addr_space PathState *state, Ray *ray, BsdfEval *eval, bool *is_lamp
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#ifdef __SPLIT_KERNEL__
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, ShaderData *sd_DL
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#endif
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)
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{
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if(ls->pdf == 0.0f)
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return false;
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/* todo: implement */
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differential3 dD = differential3_zero();
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/* evaluate closure */
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float3 light_eval = direct_emissive_eval(kg, ls, state, -ls->D, dD, ls->t, ccl_fetch(sd, time)
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#ifdef __SPLIT_KERNEL__
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,sd_DL
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#endif
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);
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if(is_zero(light_eval))
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return false;
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/* evaluate BSDF at shading point */
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#ifdef __VOLUME__
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if(ccl_fetch(sd, prim) != PRIM_NONE)
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shader_bsdf_eval(kg, sd, ls->D, eval, ls->pdf, ls->shader & SHADER_USE_MIS);
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else {
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float bsdf_pdf;
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shader_volume_phase_eval(kg, sd, ls->D, eval, &bsdf_pdf);
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if(ls->shader & SHADER_USE_MIS) {
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/* Multiple importance sampling. */
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float mis_weight = power_heuristic(ls->pdf, bsdf_pdf);
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light_eval *= mis_weight;
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}
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}
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#else
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shader_bsdf_eval(kg, sd, ls->D, eval, ls->pdf, ls->shader & SHADER_USE_MIS);
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#endif
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bsdf_eval_mul(eval, light_eval/ls->pdf);
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#ifdef __PASSES__
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/* use visibility flag to skip lights */
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if(ls->shader & SHADER_EXCLUDE_ANY) {
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if(ls->shader & SHADER_EXCLUDE_DIFFUSE)
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eval->diffuse = make_float3(0.0f, 0.0f, 0.0f);
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if(ls->shader & SHADER_EXCLUDE_GLOSSY)
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eval->glossy = make_float3(0.0f, 0.0f, 0.0f);
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if(ls->shader & SHADER_EXCLUDE_TRANSMIT)
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eval->transmission = make_float3(0.0f, 0.0f, 0.0f);
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if(ls->shader & SHADER_EXCLUDE_SCATTER)
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eval->scatter = make_float3(0.0f, 0.0f, 0.0f);
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}
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#endif
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if(bsdf_eval_is_zero(eval))
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return false;
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if(ls->shader & SHADER_CAST_SHADOW) {
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/* setup ray */
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bool transmit = (dot(ccl_fetch(sd, Ng), ls->D) < 0.0f);
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ray->P = ray_offset(ccl_fetch(sd, P), (transmit)? -ccl_fetch(sd, Ng): ccl_fetch(sd, Ng));
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if(ls->t == FLT_MAX) {
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/* distant light */
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ray->D = ls->D;
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ray->t = ls->t;
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}
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else {
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/* other lights, avoid self-intersection */
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ray->D = ray_offset(ls->P, ls->Ng) - ray->P;
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ray->D = normalize_len(ray->D, &ray->t);
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}
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ray->dP = ccl_fetch(sd, dP);
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ray->dD = differential3_zero();
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}
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else {
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/* signal to not cast shadow ray */
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ray->t = 0.0f;
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}
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/* return if it's a lamp for shadow pass */
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*is_lamp = (ls->prim == PRIM_NONE && ls->type != LIGHT_BACKGROUND);
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return true;
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}
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/* Indirect Primitive Emission */
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ccl_device_noinline float3 indirect_primitive_emission(KernelGlobals *kg, ShaderData *sd, float t, int path_flag, float bsdf_pdf)
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{
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/* evaluate emissive closure */
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float3 L = shader_emissive_eval(kg, sd);
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#ifdef __HAIR__
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if(!(path_flag & PATH_RAY_MIS_SKIP) && (ccl_fetch(sd, flag) & SD_USE_MIS) && (ccl_fetch(sd, type) & PRIMITIVE_ALL_TRIANGLE))
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#else
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if(!(path_flag & PATH_RAY_MIS_SKIP) && (ccl_fetch(sd, flag) & SD_USE_MIS))
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#endif
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{
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/* multiple importance sampling, get triangle light pdf,
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* and compute weight with respect to BSDF pdf */
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float pdf = triangle_light_pdf(kg, ccl_fetch(sd, Ng), ccl_fetch(sd, I), t);
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float mis_weight = power_heuristic(bsdf_pdf, pdf);
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return L*mis_weight;
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}
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return L;
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}
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/* Indirect Lamp Emission */
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ccl_device_noinline bool indirect_lamp_emission(KernelGlobals *kg, ccl_addr_space PathState *state, Ray *ray, float3 *emission
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#ifdef __SPLIT_KERNEL__
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,ShaderData *sd
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#endif
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)
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{
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bool hit_lamp = false;
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*emission = make_float3(0.0f, 0.0f, 0.0f);
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for(int lamp = 0; lamp < kernel_data.integrator.num_all_lights; lamp++) {
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LightSample ls;
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if(!lamp_light_eval(kg, lamp, ray->P, ray->D, ray->t, &ls))
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continue;
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#ifdef __PASSES__
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/* use visibility flag to skip lights */
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if(ls.shader & SHADER_EXCLUDE_ANY) {
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if(((ls.shader & SHADER_EXCLUDE_DIFFUSE) && (state->flag & PATH_RAY_DIFFUSE)) ||
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((ls.shader & SHADER_EXCLUDE_GLOSSY) &&
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((state->flag & (PATH_RAY_GLOSSY|PATH_RAY_REFLECT)) == (PATH_RAY_GLOSSY|PATH_RAY_REFLECT))) ||
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((ls.shader & SHADER_EXCLUDE_TRANSMIT) && (state->flag & PATH_RAY_TRANSMIT)) ||
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((ls.shader & SHADER_EXCLUDE_SCATTER) && (state->flag & PATH_RAY_VOLUME_SCATTER)))
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continue;
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}
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#endif
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float3 L = direct_emissive_eval(kg, &ls, state, -ray->D, ray->dD, ls.t, ray->time
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#ifdef __SPLIT_KERNEL__
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,sd
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#endif
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);
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#ifdef __VOLUME__
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if(state->volume_stack[0].shader != SHADER_NONE) {
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/* shadow attenuation */
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Ray volume_ray = *ray;
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volume_ray.t = ls.t;
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float3 volume_tp = make_float3(1.0f, 1.0f, 1.0f);
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kernel_volume_shadow(kg, state, &volume_ray, &volume_tp);
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L *= volume_tp;
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}
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#endif
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if(!(state->flag & PATH_RAY_MIS_SKIP)) {
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/* multiple importance sampling, get regular light pdf,
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* and compute weight with respect to BSDF pdf */
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float mis_weight = power_heuristic(state->ray_pdf, ls.pdf);
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L *= mis_weight;
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}
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*emission += L;
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hit_lamp = true;
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}
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return hit_lamp;
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}
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/* Indirect Background */
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ccl_device_noinline float3 indirect_background(KernelGlobals *kg, ccl_addr_space PathState *state, ccl_addr_space Ray *ray
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#ifdef __SPLIT_KERNEL__
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,ShaderData *sd_global
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#endif
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)
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{
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#ifdef __BACKGROUND__
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int shader = kernel_data.background.surface_shader;
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/* use visibility flag to skip lights */
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if(shader & SHADER_EXCLUDE_ANY) {
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if(((shader & SHADER_EXCLUDE_DIFFUSE) && (state->flag & PATH_RAY_DIFFUSE)) ||
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((shader & SHADER_EXCLUDE_GLOSSY) &&
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((state->flag & (PATH_RAY_GLOSSY|PATH_RAY_REFLECT)) == (PATH_RAY_GLOSSY|PATH_RAY_REFLECT))) ||
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((shader & SHADER_EXCLUDE_TRANSMIT) && (state->flag & PATH_RAY_TRANSMIT)) ||
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((shader & SHADER_EXCLUDE_CAMERA) && (state->flag & PATH_RAY_CAMERA)) ||
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((shader & SHADER_EXCLUDE_SCATTER) && (state->flag & PATH_RAY_VOLUME_SCATTER)))
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return make_float3(0.0f, 0.0f, 0.0f);
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}
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#ifdef __SPLIT_KERNEL__
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/* evaluate background closure */
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Ray priv_ray = *ray;
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shader_setup_from_background(kg, sd_global, &priv_ray);
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path_state_modify_bounce(state, true);
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float3 L = shader_eval_background(kg, sd_global, state, state->flag, SHADER_CONTEXT_EMISSION);
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path_state_modify_bounce(state, false);
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#else
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ShaderData sd;
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shader_setup_from_background(kg, &sd, ray);
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path_state_modify_bounce(state, true);
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float3 L = shader_eval_background(kg, &sd, state, state->flag, SHADER_CONTEXT_EMISSION);
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path_state_modify_bounce(state, false);
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#endif
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#ifdef __BACKGROUND_MIS__
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/* check if background light exists or if we should skip pdf */
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int res = kernel_data.integrator.pdf_background_res;
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if(!(state->flag & PATH_RAY_MIS_SKIP) && res) {
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/* multiple importance sampling, get background light pdf for ray
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* direction, and compute weight with respect to BSDF pdf */
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float pdf = background_light_pdf(kg, ray->P, ray->D);
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float mis_weight = power_heuristic(state->ray_pdf, pdf);
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return L*mis_weight;
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}
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#endif
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return L;
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#else
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return make_float3(0.8f, 0.8f, 0.8f);
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#endif
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}
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CCL_NAMESPACE_END
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