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/*
* Copyright 2011-2013 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_adaptive_sampling.h"
#include "kernel_random.h"
#include "kernel_shadow_catcher.h"
#include "kernel_write_passes.h"
CCL_NAMESPACE_BEGIN
/* --------------------------------------------------------------------
* BSDF Evaluation
*
* BSDF evaluation result, split between diffuse and glossy. This is used to
* accumulate render passes separately. Note that reflection, transmission
* and volume scattering are written to different render passes, but we assume
* that only one of those can happen at a bounce, and so do not need to accumulate
* them separately. */
ccl_device_inline void bsdf_eval_init(ccl_private BsdfEval *eval,
const bool is_diffuse,
float3 value)
{
eval->diffuse = zero_float3();
eval->glossy = zero_float3();
if (is_diffuse) {
eval->diffuse = value;
}
else {
eval->glossy = value;
}
}
ccl_device_inline void bsdf_eval_accum(ccl_private BsdfEval *eval,
const bool is_diffuse,
float3 value,
float mis_weight)
{
value *= mis_weight;
if (is_diffuse) {
eval->diffuse += value;
}
else {
eval->glossy += value;
}
}
ccl_device_inline bool bsdf_eval_is_zero(ccl_private BsdfEval *eval)
{
return is_zero(eval->diffuse) && is_zero(eval->glossy);
}
ccl_device_inline void bsdf_eval_mul(ccl_private BsdfEval *eval, float value)
{
eval->diffuse *= value;
eval->glossy *= value;
}
ccl_device_inline void bsdf_eval_mul3(ccl_private BsdfEval *eval, float3 value)
{
eval->diffuse *= value;
eval->glossy *= value;
}
ccl_device_inline float3 bsdf_eval_sum(ccl_private const BsdfEval *eval)
{
return eval->diffuse + eval->glossy;
}
ccl_device_inline float3 bsdf_eval_diffuse_glossy_ratio(ccl_private const BsdfEval *eval)
{
/* Ratio of diffuse and glossy to recover proportions for writing to render pass.
* We assume reflection, transmission and volume scatter to be exclusive. */
return safe_divide_float3_float3(eval->diffuse, eval->diffuse + eval->glossy);
}
/* --------------------------------------------------------------------
* Clamping
*
* Clamping is done on a per-contribution basis so that we can write directly
* to render buffers instead of using per-thread memory, and to avoid the
* impact of clamping on other contributions. */
ccl_device_forceinline void kernel_accum_clamp(KernelGlobals kg, ccl_private float3 *L, int bounce)
{
#ifdef __KERNEL_DEBUG_NAN__
if (!isfinite3_safe(*L)) {
kernel_assert(!"Cycles sample with non-finite value detected");
}
#endif
/* Make sure all components are finite, allowing the contribution to be usable by adaptive
* sampling convergence check, but also to make it so render result never causes issues with
* post-processing. */
*L = ensure_finite3(*L);
#ifdef __CLAMP_SAMPLE__
float limit = (bounce > 0) ? kernel_data.integrator.sample_clamp_indirect :
kernel_data.integrator.sample_clamp_direct;
float sum = reduce_add(fabs(*L));
if (sum > limit) {
*L *= limit / sum;
}
#endif
}
/* --------------------------------------------------------------------
* Pass accumulation utilities.
*/
/* Get pointer to pixel in render buffer. */
ccl_device_forceinline ccl_global float *kernel_accum_pixel_render_buffer(
KernelGlobals kg, ConstIntegratorState state, ccl_global float *ccl_restrict render_buffer)
{
const uint32_t render_pixel_index = INTEGRATOR_STATE(state, path, render_pixel_index);
const uint64_t render_buffer_offset = (uint64_t)render_pixel_index *
kernel_data.film.pass_stride;
return render_buffer + render_buffer_offset;
}
/* --------------------------------------------------------------------
* Adaptive sampling.
*/
ccl_device_inline int kernel_accum_sample(KernelGlobals kg,
ConstIntegratorState state,
ccl_global float *ccl_restrict render_buffer,
int sample)
{
if (kernel_data.film.pass_sample_count == PASS_UNUSED) {
return sample;
}
ccl_global float *buffer = kernel_accum_pixel_render_buffer(kg, state, render_buffer);
return atomic_fetch_and_add_uint32((uint *)(buffer) + kernel_data.film.pass_sample_count, 1);
}
ccl_device void kernel_accum_adaptive_buffer(KernelGlobals kg,
ConstIntegratorState state,
const float3 contribution,
ccl_global float *ccl_restrict buffer)
{
/* Adaptive Sampling. Fill the additional buffer with the odd samples and calculate our stopping
* criteria. This is the heuristic from "A hierarchical automatic stopping condition for Monte
* Carlo global illumination" except that here it is applied per pixel and not in hierarchical
* tiles. */
if (kernel_data.film.pass_adaptive_aux_buffer == PASS_UNUSED) {
return;
}
const int sample = INTEGRATOR_STATE(state, path, sample);
if (sample_is_even(kernel_data.integrator.sampling_pattern, sample)) {
kernel_write_pass_float4(
buffer + kernel_data.film.pass_adaptive_aux_buffer,
make_float4(contribution.x * 2.0f, contribution.y * 2.0f, contribution.z * 2.0f, 0.0f));
}
}
/* --------------------------------------------------------------------
* Shadow catcher.
*/
#ifdef __SHADOW_CATCHER__
/* Accumulate contribution to the Shadow Catcher pass.
*
* Returns truth if the contribution is fully handled here and is not to be added to the other
* passes (like combined, adaptive sampling). */
ccl_device bool kernel_accum_shadow_catcher(KernelGlobals kg,
ConstIntegratorState state,
const float3 contribution,
ccl_global float *ccl_restrict buffer)
{
if (!kernel_data.integrator.has_shadow_catcher) {
return false;
}
kernel_assert(kernel_data.film.pass_shadow_catcher != PASS_UNUSED);
kernel_assert(kernel_data.film.pass_shadow_catcher_matte != PASS_UNUSED);
/* Matte pass. */
if (kernel_shadow_catcher_is_matte_path(kg, state)) {
kernel_write_pass_float3(buffer + kernel_data.film.pass_shadow_catcher_matte, contribution);
/* NOTE: Accumulate the combined pass and to the samples count pass, so that the adaptive
* sampling is based on how noisy the combined pass is as if there were no catchers in the
* scene. */
}
/* Shadow catcher pass. */
if (kernel_shadow_catcher_is_object_pass(kg, state)) {
kernel_write_pass_float3(buffer + kernel_data.film.pass_shadow_catcher, contribution);
return true;
}
return false;
}
ccl_device bool kernel_accum_shadow_catcher_transparent(KernelGlobals kg,
ConstIntegratorState state,
const float3 contribution,
const float transparent,
ccl_global float *ccl_restrict buffer)
{
if (!kernel_data.integrator.has_shadow_catcher) {
return false;
}
kernel_assert(kernel_data.film.pass_shadow_catcher != PASS_UNUSED);
kernel_assert(kernel_data.film.pass_shadow_catcher_matte != PASS_UNUSED);
if (INTEGRATOR_STATE(state, path, flag) & PATH_RAY_SHADOW_CATCHER_BACKGROUND) {
return true;
}
/* Matte pass. */
if (kernel_shadow_catcher_is_matte_path(kg, state)) {
kernel_write_pass_float4(
buffer + kernel_data.film.pass_shadow_catcher_matte,
make_float4(contribution.x, contribution.y, contribution.z, transparent));
/* NOTE: Accumulate the combined pass and to the samples count pass, so that the adaptive
* sampling is based on how noisy the combined pass is as if there were no catchers in the
* scene. */
}
/* Shadow catcher pass. */
if (kernel_shadow_catcher_is_object_pass(kg, state)) {
/* NOTE: The transparency of the shadow catcher pass is ignored. It is not needed for the
* calculation and the alpha channel of the pass contains numbers of samples contributed to a
* pixel of the pass. */
kernel_write_pass_float3(buffer + kernel_data.film.pass_shadow_catcher, contribution);
return true;
}
return false;
}
ccl_device void kernel_accum_shadow_catcher_transparent_only(KernelGlobals kg,
ConstIntegratorState state,
const float transparent,
ccl_global float *ccl_restrict buffer)
{
if (!kernel_data.integrator.has_shadow_catcher) {
return;
}
kernel_assert(kernel_data.film.pass_shadow_catcher_matte != PASS_UNUSED);
/* Matte pass. */
if (kernel_shadow_catcher_is_matte_path(kg, state)) {
kernel_write_pass_float(buffer + kernel_data.film.pass_shadow_catcher_matte + 3, transparent);
}
}
#endif /* __SHADOW_CATCHER__ */
/* --------------------------------------------------------------------
* Render passes.
*/
/* Write combined pass. */
ccl_device_inline void kernel_accum_combined_pass(KernelGlobals kg,
ConstIntegratorState state,
const float3 contribution,
ccl_global float *ccl_restrict buffer)
{
#ifdef __SHADOW_CATCHER__
if (kernel_accum_shadow_catcher(kg, state, contribution, buffer)) {
return;
}
#endif
if (kernel_data.film.light_pass_flag & PASSMASK(COMBINED)) {
kernel_write_pass_float3(buffer + kernel_data.film.pass_combined, contribution);
}
kernel_accum_adaptive_buffer(kg, state, contribution, buffer);
}
/* Write combined pass with transparency. */
ccl_device_inline void kernel_accum_combined_transparent_pass(KernelGlobals kg,
ConstIntegratorState state,
const float3 contribution,
const float transparent,
ccl_global float *ccl_restrict
buffer)
{
#ifdef __SHADOW_CATCHER__
if (kernel_accum_shadow_catcher_transparent(kg, state, contribution, transparent, buffer)) {
return;
}
#endif
if (kernel_data.film.light_pass_flag & PASSMASK(COMBINED)) {
kernel_write_pass_float4(
buffer + kernel_data.film.pass_combined,
make_float4(contribution.x, contribution.y, contribution.z, transparent));
}
kernel_accum_adaptive_buffer(kg, state, contribution, buffer);
}
/* Write background or emission to appropriate pass. */
ccl_device_inline void kernel_accum_emission_or_background_pass(KernelGlobals kg,
ConstIntegratorState state,
float3 contribution,
ccl_global float *ccl_restrict
buffer,
const int pass)
{
if (!(kernel_data.film.light_pass_flag & PASS_ANY)) {
return;
}
#ifdef __PASSES__
const int path_flag = INTEGRATOR_STATE(state, path, flag);
int pass_offset = PASS_UNUSED;
/* Denoising albedo. */
# ifdef __DENOISING_FEATURES__
if (path_flag & PATH_RAY_DENOISING_FEATURES) {
if (kernel_data.film.pass_denoising_albedo != PASS_UNUSED) {
const float3 denoising_feature_throughput = INTEGRATOR_STATE(
state, path, denoising_feature_throughput);
const float3 denoising_albedo = denoising_feature_throughput * contribution;
kernel_write_pass_float3(buffer + kernel_data.film.pass_denoising_albedo, denoising_albedo);
}
}
# endif /* __DENOISING_FEATURES__ */
if (!(path_flag & PATH_RAY_ANY_PASS)) {
/* Directly visible, write to emission or background pass. */
pass_offset = pass;
}
else if (path_flag & (PATH_RAY_REFLECT_PASS | PATH_RAY_TRANSMISSION_PASS)) {
/* Indirectly visible through reflection. */
const int glossy_pass_offset = (path_flag & PATH_RAY_REFLECT_PASS) ?
((INTEGRATOR_STATE(state, path, bounce) == 1) ?
kernel_data.film.pass_glossy_direct :
kernel_data.film.pass_glossy_indirect) :
((INTEGRATOR_STATE(state, path, bounce) == 1) ?
kernel_data.film.pass_transmission_direct :
kernel_data.film.pass_transmission_indirect);
if (glossy_pass_offset != PASS_UNUSED) {
/* Glossy is a subset of the throughput, reconstruct it here using the
* diffuse-glossy ratio. */
const float3 ratio = INTEGRATOR_STATE(state, path, diffuse_glossy_ratio);
const float3 glossy_contribution = (one_float3() - ratio) * contribution;
kernel_write_pass_float3(buffer + glossy_pass_offset, glossy_contribution);
}
/* Reconstruct diffuse subset of throughput. */
pass_offset = (INTEGRATOR_STATE(state, path, bounce) == 1) ?
kernel_data.film.pass_diffuse_direct :
kernel_data.film.pass_diffuse_indirect;
if (pass_offset != PASS_UNUSED) {
contribution *= INTEGRATOR_STATE(state, path, diffuse_glossy_ratio);
}
}
else if (path_flag & PATH_RAY_VOLUME_PASS) {
/* Indirectly visible through volume. */
pass_offset = (INTEGRATOR_STATE(state, path, bounce) == 1) ?
kernel_data.film.pass_volume_direct :
kernel_data.film.pass_volume_indirect;
}
/* Single write call for GPU coherence. */
if (pass_offset != PASS_UNUSED) {
kernel_write_pass_float3(buffer + pass_offset, contribution);
}
#endif /* __PASSES__ */
}
/* Write light contribution to render buffer. */
ccl_device_inline void kernel_accum_light(KernelGlobals kg,
ConstIntegratorState state,
ccl_global float *ccl_restrict render_buffer)
{
/* The throughput for shadow paths already contains the light shader evaluation. */
float3 contribution = INTEGRATOR_STATE(state, shadow_path, throughput);
kernel_accum_clamp(kg, &contribution, INTEGRATOR_STATE(state, shadow_path, bounce));
ccl_global float *buffer = kernel_accum_pixel_render_buffer(kg, state, render_buffer);
kernel_accum_combined_pass(kg, state, contribution, buffer);
#ifdef __PASSES__
if (kernel_data.film.light_pass_flag & PASS_ANY) {
const int path_flag = INTEGRATOR_STATE(state, shadow_path, flag);
int pass_offset = PASS_UNUSED;
if (path_flag & (PATH_RAY_REFLECT_PASS | PATH_RAY_TRANSMISSION_PASS)) {
/* Indirectly visible through reflection. */
const int glossy_pass_offset = (path_flag & PATH_RAY_REFLECT_PASS) ?
((INTEGRATOR_STATE(state, shadow_path, bounce) == 0) ?
kernel_data.film.pass_glossy_direct :
kernel_data.film.pass_glossy_indirect) :
((INTEGRATOR_STATE(state, shadow_path, bounce) == 0) ?
kernel_data.film.pass_transmission_direct :
kernel_data.film.pass_transmission_indirect);
if (glossy_pass_offset != PASS_UNUSED) {
/* Glossy is a subset of the throughput, reconstruct it here using the
* diffuse-glossy ratio. */
const float3 ratio = INTEGRATOR_STATE(state, shadow_path, diffuse_glossy_ratio);
const float3 glossy_contribution = (one_float3() - ratio) * contribution;
kernel_write_pass_float3(buffer + glossy_pass_offset, glossy_contribution);
}
/* Reconstruct diffuse subset of throughput. */
pass_offset = (INTEGRATOR_STATE(state, shadow_path, bounce) == 0) ?
kernel_data.film.pass_diffuse_direct :
kernel_data.film.pass_diffuse_indirect;
if (pass_offset != PASS_UNUSED) {
contribution *= INTEGRATOR_STATE(state, shadow_path, diffuse_glossy_ratio);
}
}
else if (path_flag & PATH_RAY_VOLUME_PASS) {
/* Indirectly visible through volume. */
pass_offset = (INTEGRATOR_STATE(state, shadow_path, bounce) == 0) ?
kernel_data.film.pass_volume_direct :
kernel_data.film.pass_volume_indirect;
}
/* Single write call for GPU coherence. */
if (pass_offset != PASS_UNUSED) {
kernel_write_pass_float3(buffer + pass_offset, contribution);
}
/* Write shadow pass. */
if (kernel_data.film.pass_shadow != PASS_UNUSED && (path_flag & PATH_RAY_SHADOW_FOR_LIGHT) &&
(path_flag & PATH_RAY_CAMERA)) {
const float3 unshadowed_throughput = INTEGRATOR_STATE(
state, shadow_path, unshadowed_throughput);
const float3 shadowed_throughput = INTEGRATOR_STATE(state, shadow_path, throughput);
const float3 shadow = safe_divide_float3_float3(shadowed_throughput, unshadowed_throughput) *
kernel_data.film.pass_shadow_scale;
kernel_write_pass_float3(buffer + kernel_data.film.pass_shadow, shadow);
}
}
#endif
}
/* Write transparency to render buffer.
*
* Note that we accumulate transparency = 1 - alpha in the render buffer.
* Otherwise we'd have to write alpha on path termination, which happens
* in many places. */
ccl_device_inline void kernel_accum_transparent(KernelGlobals kg,
ConstIntegratorState state,
const float transparent,
ccl_global float *ccl_restrict render_buffer)
{
ccl_global float *buffer = kernel_accum_pixel_render_buffer(kg, state, render_buffer);
if (kernel_data.film.light_pass_flag & PASSMASK(COMBINED)) {
kernel_write_pass_float(buffer + kernel_data.film.pass_combined + 3, transparent);
}
kernel_accum_shadow_catcher_transparent_only(kg, state, transparent, buffer);
}
/* Write background contribution to render buffer.
*
* Includes transparency, matching kernel_accum_transparent. */
ccl_device_inline void kernel_accum_background(KernelGlobals kg,
ConstIntegratorState state,
const float3 L,
const float transparent,
const bool is_transparent_background_ray,
ccl_global float *ccl_restrict render_buffer)
{
float3 contribution = INTEGRATOR_STATE(state, path, throughput) * L;
kernel_accum_clamp(kg, &contribution, INTEGRATOR_STATE(state, path, bounce) - 1);
ccl_global float *buffer = kernel_accum_pixel_render_buffer(kg, state, render_buffer);
if (is_transparent_background_ray) {
kernel_accum_transparent(kg, state, transparent, render_buffer);
}
else {
kernel_accum_combined_transparent_pass(kg, state, contribution, transparent, buffer);
}
kernel_accum_emission_or_background_pass(
kg, state, contribution, buffer, kernel_data.film.pass_background);
}
/* Write emission to render buffer. */
ccl_device_inline void kernel_accum_emission(KernelGlobals kg,
ConstIntegratorState state,
const float3 throughput,
const float3 L,
ccl_global float *ccl_restrict render_buffer)
{
float3 contribution = throughput * L;
kernel_accum_clamp(kg, &contribution, INTEGRATOR_STATE(state, path, bounce) - 1);
ccl_global float *buffer = kernel_accum_pixel_render_buffer(kg, state, render_buffer);
kernel_accum_combined_pass(kg, state, contribution, buffer);
kernel_accum_emission_or_background_pass(
kg, state, contribution, buffer, kernel_data.film.pass_emission);
}
CCL_NAMESPACE_END
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