353 lines
11 KiB
C
353 lines
11 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_cpu float3 direct_emissive_eval(KernelGlobals *kg,
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ShaderData *emission_sd,
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LightSample *ls,
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ccl_addr_space PathState *state,
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float3 I,
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differential3 dI,
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float t,
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float time)
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{
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/* setup shading at emitter */
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float3 eval = make_float3(0.0f, 0.0f, 0.0f);
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if (shader_constant_emission_eval(kg, ls->shader, &eval)) {
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if ((ls->prim != PRIM_NONE) && dot(ls->Ng, I) < 0.0f) {
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ls->Ng = -ls->Ng;
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}
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}
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else {
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/* Setup shader data and call shader_eval_surface once, better
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* for GPU coherence and compile times. */
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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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ray.time = time;
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ray.dP = differential3_zero();
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ray.dD = dI;
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shader_setup_from_background(kg, emission_sd, &ray);
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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,
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emission_sd,
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ls->P,
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ls->Ng,
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I,
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ls->shader,
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ls->object,
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ls->prim,
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ls->u,
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ls->v,
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t,
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time,
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false,
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ls->lamp);
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ls->Ng = emission_sd->Ng;
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}
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/* No proper path flag, we're evaluating this for all closures. that's
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* weak but 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, emission_sd, state, PATH_RAY_EMISSION);
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path_state_modify_bounce(state, false);
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/* Evaluate closures. */
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#ifdef __BACKGROUND_MIS__
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if (ls->type == LIGHT_BACKGROUND) {
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eval = shader_background_eval(emission_sd);
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}
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else
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#endif
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{
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eval = shader_emissive_eval(emission_sd);
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}
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}
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eval *= ls->eval_fac;
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if (ls->lamp != LAMP_NONE) {
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const ccl_global KernelLight *klight = &kernel_tex_fetch(__lights, ls->lamp);
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eval *= make_float3(klight->strength[0], klight->strength[1], klight->strength[2]);
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}
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return eval;
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}
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ccl_device_noinline_cpu bool direct_emission(KernelGlobals *kg,
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ShaderData *sd,
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ShaderData *emission_sd,
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LightSample *ls,
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ccl_addr_space PathState *state,
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Ray *ray,
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BsdfEval *eval,
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bool *is_lamp,
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float rand_terminate)
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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(
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kg, emission_sd, ls, state, -ls->D, dD, ls->t, sd->time);
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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 (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_mul3(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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eval->subsurface = make_float3(0.0f, 0.0f, 0.0f);
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}
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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 (kernel_data.integrator.light_inv_rr_threshold > 0.0f
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#ifdef __SHADOW_TRICKS__
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&& (state->flag & PATH_RAY_SHADOW_CATCHER) == 0
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#endif
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) {
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float probability = max3(fabs(bsdf_eval_sum(eval))) *
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kernel_data.integrator.light_inv_rr_threshold;
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if (probability < 1.0f) {
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if (rand_terminate >= probability) {
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return false;
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}
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bsdf_eval_mul(eval, 1.0f / probability);
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}
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}
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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_cpu float3 indirect_primitive_emission(
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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(sd);
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#ifdef __HAIR__
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if (!(path_flag & PATH_RAY_MIS_SKIP) && (sd->flag & SD_USE_MIS) &&
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(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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{
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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, 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_cpu bool indirect_lamp_emission(KernelGlobals *kg,
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ShaderData *emission_sd,
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ccl_addr_space PathState *state,
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Ray *ray,
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float3 *emission)
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{
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bool hit_lamp = false;
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for (int lamp = 0; lamp < kernel_data.integrator.num_all_lights; lamp++) {
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LightSample ls ccl_optional_struct_init;
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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)) ==
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(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(
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kg, emission_sd, &ls, state, -ray->D, ray->dD, ls.t, ray->time);
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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, emission_sd, 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_cpu float3 indirect_background(KernelGlobals *kg,
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ShaderData *emission_sd,
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ccl_addr_space PathState *state,
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ccl_addr_space 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) &&
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((state->flag & (PATH_RAY_GLOSSY | PATH_RAY_REFLECT)) ==
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(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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/* Evaluate background shader. */
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float3 L = make_float3(0.0f, 0.0f, 0.0f);
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if (!shader_constant_emission_eval(kg, shader, &L)) {
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# ifdef __SPLIT_KERNEL__
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Ray priv_ray = *ray;
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shader_setup_from_background(kg, emission_sd, &priv_ray);
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# else
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shader_setup_from_background(kg, emission_sd, ray);
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# endif
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path_state_modify_bounce(state, true);
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shader_eval_surface(kg, emission_sd, state, state->flag | PATH_RAY_EMISSION);
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path_state_modify_bounce(state, false);
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L = shader_background_eval(emission_sd);
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}
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/* Background MIS weights. */
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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_x = kernel_data.integrator.pdf_background_res_x;
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if (!(state->flag & PATH_RAY_MIS_SKIP) && res_x) {
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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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