forked from bartvdbraak/blender
264 lines
7.2 KiB
C
264 lines
7.2 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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/* Direction Emission */
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ccl_device_noinline float3 direct_emissive_eval(KernelGlobals *kg,
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LightSample *ls, float3 I, differential3 dI, float t, float time, int bounce, int transparent_bounce)
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{
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/* setup shading at emitter */
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ShaderData sd;
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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, bounce+1, transparent_bounce);
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eval = shader_eval_background(kg, &sd, 0, SHADER_CONTEXT_EMISSION);
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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, bounce+1, transparent_bounce);
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ls->Ng = 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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shader_eval_surface(kg, &sd, 0.0f, 0, SHADER_CONTEXT_EMISSION);
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/* evaluate emissive closure */
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if(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, int lindex,
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float randt, float randu, float randv, Ray *ray, BsdfEval *eval,
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bool *is_lamp, int bounce, int transparent_bounce)
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{
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LightSample ls;
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#ifdef __BRANCHED_PATH__
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if(lindex != LAMP_NONE) {
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/* sample position on a specified light */
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light_select(kg, lindex, randu, randv, sd->P, &ls);
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}
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else
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#endif
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{
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/* sample a light and position on int */
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light_sample(kg, randt, randu, randv, sd->time, sd->P, &ls);
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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, -ls.D, dD, ls.t, sd->time, bounce, transparent_bounce);
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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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float bsdf_pdf;
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#ifdef __VOLUME__
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if(sd->prim != PRIM_NONE)
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shader_bsdf_eval(kg, sd, ls.D, eval, &bsdf_pdf);
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else
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shader_volume_phase_eval(kg, sd, ls.D, eval, &bsdf_pdf);
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#else
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shader_bsdf_eval(kg, sd, ls.D, eval, &bsdf_pdf);
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#endif
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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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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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}
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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(sd->Ng, ls.D) < 0.0f);
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ray->P = ray_offset(sd->P, (transmit)? -sd->Ng: 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 = 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) && (sd->flag & SD_USE_MIS) && (sd->type & PRIMITIVE_ALL_TRIANGLE)) {
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#else
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if(!(path_flag & PATH_RAY_MIS_SKIP) && (sd->flag & SD_USE_MIS)) {
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#endif
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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, sd->Ng, 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, PathState *state, Ray *ray, float randt, float3 *emission)
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{
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LightSample ls;
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int lamp = lamp_light_eval_sample(kg, randt);
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if(lamp == LAMP_NONE)
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return false;
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if(!lamp_light_eval(kg, lamp, ray->P, ray->D, ray->t, &ls))
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return false;
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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) && (state->flag & PATH_RAY_GLOSSY)) ||
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((ls.shader & SHADER_EXCLUDE_TRANSMIT) && (state->flag & PATH_RAY_TRANSMIT)))
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return false;
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}
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#endif
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float3 L = direct_emissive_eval(kg, &ls, -ray->D, ray->dD, ls.t, ray->time, state->bounce, state->transparent_bounce);
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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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return true;
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}
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/* Indirect Background */
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ccl_device_noinline float3 indirect_background(KernelGlobals *kg, PathState *state, Ray *ray)
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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) && (state->flag & PATH_RAY_GLOSSY)) ||
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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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return make_float3(0.0f, 0.0f, 0.0f);
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}
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/* evaluate background closure */
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ShaderData sd;
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shader_setup_from_background(kg, &sd, ray, state->bounce+1, state->transparent_bounce);
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float3 L = shader_eval_background(kg, &sd, state->flag, SHADER_CONTEXT_EMISSION);
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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->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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