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/*
* Copyright 2011-2021 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include "kernel/film/accumulate.h"
#include "kernel/integrator/shader_eval.h"
#include "kernel/light/light.h"
#include "kernel/light/sample.h"
#include "kernel/sample/mis.h"
CCL_NAMESPACE_BEGIN
ccl_device float3 integrator_eval_background_shader(KernelGlobals kg,
IntegratorState state,
ccl_global float *ccl_restrict render_buffer)
{
#ifdef __BACKGROUND__
const int shader = kernel_data.background.surface_shader;
const uint32_t path_flag = INTEGRATOR_STATE(state, path, flag);
/* Use visibility flag to skip lights. */
if (shader & SHADER_EXCLUDE_ANY) {
if (((shader & SHADER_EXCLUDE_DIFFUSE) && (path_flag & PATH_RAY_DIFFUSE)) ||
((shader & SHADER_EXCLUDE_GLOSSY) && ((path_flag & (PATH_RAY_GLOSSY | PATH_RAY_REFLECT)) ==
(PATH_RAY_GLOSSY | PATH_RAY_REFLECT))) ||
((shader & SHADER_EXCLUDE_TRANSMIT) && (path_flag & PATH_RAY_TRANSMIT)) ||
((shader & SHADER_EXCLUDE_CAMERA) && (path_flag & PATH_RAY_CAMERA)) ||
((shader & SHADER_EXCLUDE_SCATTER) && (path_flag & PATH_RAY_VOLUME_SCATTER)))
return zero_float3();
}
/* Use fast constant background color if available. */
float3 L = zero_float3();
if (!shader_constant_emission_eval(kg, shader, &L)) {
/* Evaluate background shader. */
/* TODO: does aliasing like this break automatic SoA in CUDA?
* Should we instead store closures separate from ShaderData? */
ShaderDataTinyStorage emission_sd_storage;
ccl_private ShaderData *emission_sd = AS_SHADER_DATA(&emission_sd_storage);
PROFILING_INIT_FOR_SHADER(kg, PROFILING_SHADE_LIGHT_SETUP);
shader_setup_from_background(kg,
emission_sd,
INTEGRATOR_STATE(state, ray, P),
INTEGRATOR_STATE(state, ray, D),
INTEGRATOR_STATE(state, ray, time));
PROFILING_SHADER(emission_sd->object, emission_sd->shader);
PROFILING_EVENT(PROFILING_SHADE_LIGHT_EVAL);
shader_eval_surface<KERNEL_FEATURE_NODE_MASK_SURFACE_LIGHT>(
kg, state, emission_sd, render_buffer, path_flag | PATH_RAY_EMISSION);
L = shader_background_eval(emission_sd);
}
/* Background MIS weights. */
# ifdef __BACKGROUND_MIS__
/* Check if background light exists or if we should skip pdf. */
if (!(INTEGRATOR_STATE(state, path, flag) & PATH_RAY_MIS_SKIP) &&
kernel_data.background.use_mis) {
const float3 ray_P = INTEGRATOR_STATE(state, ray, P);
const float3 ray_D = INTEGRATOR_STATE(state, ray, D);
const float mis_ray_pdf = INTEGRATOR_STATE(state, path, mis_ray_pdf);
const float mis_ray_t = INTEGRATOR_STATE(state, path, mis_ray_t);
/* multiple importance sampling, get background light pdf for ray
* direction, and compute weight with respect to BSDF pdf */
const float pdf = background_light_pdf(kg, ray_P - ray_D * mis_ray_t, ray_D);
const float mis_weight = power_heuristic(mis_ray_pdf, pdf);
L *= mis_weight;
}
# endif
return L;
#else
return make_float3(0.8f, 0.8f, 0.8f);
#endif
}
ccl_device_inline void integrate_background(KernelGlobals kg,
IntegratorState state,
ccl_global float *ccl_restrict render_buffer)
{
/* Accumulate transparency for transparent background. We can skip background
* shader evaluation unless a background pass is used. */
bool eval_background = true;
float transparent = 0.0f;
const bool is_transparent_background_ray = kernel_data.background.transparent &&
(INTEGRATOR_STATE(state, path, flag) &
PATH_RAY_TRANSPARENT_BACKGROUND);
if (is_transparent_background_ray) {
transparent = average(INTEGRATOR_STATE(state, path, throughput));
#ifdef __PASSES__
eval_background = (kernel_data.film.light_pass_flag & PASSMASK(BACKGROUND));
#else
eval_background = false;
#endif
}
/* Evaluate background shader. */
float3 L = (eval_background) ? integrator_eval_background_shader(kg, state, render_buffer) :
zero_float3();
/* When using the ao bounces approximation, adjust background
* shader intensity with ao factor. */
if (path_state_ao_bounce(kg, state)) {
L *= kernel_data.integrator.ao_bounces_factor;
}
/* Write to render buffer. */
kernel_accum_background(kg, state, L, transparent, is_transparent_background_ray, render_buffer);
}
ccl_device_inline void integrate_distant_lights(KernelGlobals kg,
IntegratorState state,
ccl_global float *ccl_restrict render_buffer)
{
const float3 ray_D = INTEGRATOR_STATE(state, ray, D);
const float ray_time = INTEGRATOR_STATE(state, ray, time);
LightSample ls ccl_optional_struct_init;
for (int lamp = 0; lamp < kernel_data.integrator.num_all_lights; lamp++) {
if (light_sample_from_distant_ray(kg, ray_D, lamp, &ls)) {
/* Use visibility flag to skip lights. */
#ifdef __PASSES__
const uint32_t path_flag = INTEGRATOR_STATE(state, path, flag);
if (ls.shader & SHADER_EXCLUDE_ANY) {
if (((ls.shader & SHADER_EXCLUDE_DIFFUSE) && (path_flag & PATH_RAY_DIFFUSE)) ||
((ls.shader & SHADER_EXCLUDE_GLOSSY) &&
((path_flag & (PATH_RAY_GLOSSY | PATH_RAY_REFLECT)) ==
(PATH_RAY_GLOSSY | PATH_RAY_REFLECT))) ||
((ls.shader & SHADER_EXCLUDE_TRANSMIT) && (path_flag & PATH_RAY_TRANSMIT)) ||
((ls.shader & SHADER_EXCLUDE_CAMERA) && (path_flag & PATH_RAY_CAMERA)) ||
((ls.shader & SHADER_EXCLUDE_SCATTER) && (path_flag & PATH_RAY_VOLUME_SCATTER)))
return;
}
#endif
/* Evaluate light shader. */
/* TODO: does aliasing like this break automatic SoA in CUDA? */
ShaderDataTinyStorage emission_sd_storage;
ccl_private ShaderData *emission_sd = AS_SHADER_DATA(&emission_sd_storage);
float3 light_eval = light_sample_shader_eval(kg, state, emission_sd, &ls, ray_time);
if (is_zero(light_eval)) {
return;
}
/* MIS weighting. */
if (!(path_flag & PATH_RAY_MIS_SKIP)) {
/* multiple importance sampling, get regular light pdf,
* and compute weight with respect to BSDF pdf */
const float mis_ray_pdf = INTEGRATOR_STATE(state, path, mis_ray_pdf);
const float mis_weight = power_heuristic(mis_ray_pdf, ls.pdf);
light_eval *= mis_weight;
}
/* Write to render buffer. */
const float3 throughput = INTEGRATOR_STATE(state, path, throughput);
kernel_accum_emission(kg, state, throughput, light_eval, render_buffer);
}
}
}
ccl_device void integrator_shade_background(KernelGlobals kg,
IntegratorState state,
ccl_global float *ccl_restrict render_buffer)
{
PROFILING_INIT(kg, PROFILING_SHADE_LIGHT_SETUP);
/* TODO: unify these in a single loop to only have a single shader evaluation call. */
integrate_distant_lights(kg, state, render_buffer);
integrate_background(kg, state, render_buffer);
#ifdef __SHADOW_CATCHER__
if (INTEGRATOR_STATE(state, path, flag) & PATH_RAY_SHADOW_CATCHER_BACKGROUND) {
/* Special case for shadow catcher where we want to fill the background pass
* behind the shadow catcher but also continue tracing the path. */
INTEGRATOR_STATE_WRITE(state, path, flag) &= ~PATH_RAY_SHADOW_CATCHER_BACKGROUND;
integrator_intersect_next_kernel_after_shadow_catcher_background<
DEVICE_KERNEL_INTEGRATOR_SHADE_BACKGROUND>(kg, state);
return;
}
#endif
INTEGRATOR_PATH_TERMINATE(DEVICE_KERNEL_INTEGRATOR_SHADE_BACKGROUND);
}
CCL_NAMESPACE_END
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