blender/intern/cycles/kernel/kernel_path.h
Thomas Dinges 65f21d9b43 Code cleanup / Cycles:
* Avoid special code, when Subsurface is enabled.
Ideally we should only use the function, and get rid of the extra duplicate, but this is slower on CUDA.
2013-09-04 16:11:21 +00:00

1392 lines
40 KiB
C

/*
* 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
*/
#ifdef __OSL__
#include "osl_shader.h"
#endif
#include "kernel_differential.h"
#include "kernel_montecarlo.h"
#include "kernel_projection.h"
#include "kernel_object.h"
#include "kernel_triangle.h"
#include "kernel_curve.h"
#include "kernel_primitive.h"
#include "kernel_projection.h"
#include "kernel_random.h"
#include "kernel_bvh.h"
#include "kernel_accumulate.h"
#include "kernel_camera.h"
#include "kernel_shader.h"
#include "kernel_light.h"
#include "kernel_emission.h"
#include "kernel_passes.h"
#ifdef __SUBSURFACE__
#include "kernel_subsurface.h"
#endif
CCL_NAMESPACE_BEGIN
typedef struct PathState {
int flag;
int bounce;
int diffuse_bounce;
int glossy_bounce;
int transmission_bounce;
int transparent_bounce;
} PathState;
__device_inline void path_state_init(PathState *state)
{
state->flag = PATH_RAY_CAMERA|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP;
state->bounce = 0;
state->diffuse_bounce = 0;
state->glossy_bounce = 0;
state->transmission_bounce = 0;
state->transparent_bounce = 0;
}
__device_inline void path_state_next(KernelGlobals *kg, PathState *state, int label)
{
/* ray through transparent keeps same flags from previous ray and is
* not counted as a regular bounce, transparent has separate max */
if(label & LABEL_TRANSPARENT) {
state->flag |= PATH_RAY_TRANSPARENT;
state->transparent_bounce++;
if(!kernel_data.integrator.transparent_shadows)
state->flag |= PATH_RAY_MIS_SKIP;
return;
}
state->bounce++;
/* reflection/transmission */
if(label & LABEL_REFLECT) {
state->flag |= PATH_RAY_REFLECT;
state->flag &= ~(PATH_RAY_TRANSMIT|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
if(label & LABEL_DIFFUSE)
state->diffuse_bounce++;
else
state->glossy_bounce++;
}
else {
kernel_assert(label & LABEL_TRANSMIT);
state->flag |= PATH_RAY_TRANSMIT;
state->flag &= ~(PATH_RAY_REFLECT|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
state->transmission_bounce++;
}
/* diffuse/glossy/singular */
if(label & LABEL_DIFFUSE) {
state->flag |= PATH_RAY_DIFFUSE|PATH_RAY_DIFFUSE_ANCESTOR;
state->flag &= ~(PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
}
else if(label & LABEL_GLOSSY) {
state->flag |= PATH_RAY_GLOSSY|PATH_RAY_GLOSSY_ANCESTOR;
state->flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
}
else {
kernel_assert(label & LABEL_SINGULAR);
state->flag |= PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP;
state->flag &= ~PATH_RAY_DIFFUSE;
}
}
__device_inline uint path_state_ray_visibility(KernelGlobals *kg, PathState *state)
{
uint flag = state->flag & PATH_RAY_ALL_VISIBILITY;
/* for visibility, diffuse/glossy are for reflection only */
if(flag & PATH_RAY_TRANSMIT)
flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY);
/* for camera visibility, use render layer flags */
if(flag & PATH_RAY_CAMERA)
flag |= kernel_data.integrator.layer_flag;
return flag;
}
__device_inline float path_state_terminate_probability(KernelGlobals *kg, PathState *state, const float3 throughput)
{
if(state->flag & PATH_RAY_TRANSPARENT) {
/* transparent rays treated separately */
if(state->transparent_bounce >= kernel_data.integrator.transparent_max_bounce)
return 0.0f;
else if(state->transparent_bounce <= kernel_data.integrator.transparent_min_bounce)
return 1.0f;
}
else {
/* other rays */
if((state->bounce >= kernel_data.integrator.max_bounce) ||
(state->diffuse_bounce >= kernel_data.integrator.max_diffuse_bounce) ||
(state->glossy_bounce >= kernel_data.integrator.max_glossy_bounce) ||
(state->transmission_bounce >= kernel_data.integrator.max_transmission_bounce))
{
return 0.0f;
}
else if(state->bounce <= kernel_data.integrator.min_bounce) {
return 1.0f;
}
}
/* probalistic termination */
return average(throughput); /* todo: try using max here */
}
__device_inline bool shadow_blocked(KernelGlobals *kg, PathState *state, Ray *ray, float3 *shadow)
{
*shadow = make_float3(1.0f, 1.0f, 1.0f);
if(ray->t == 0.0f)
return false;
Intersection isect;
#ifdef __HAIR__
bool result = scene_intersect(kg, ray, PATH_RAY_SHADOW_OPAQUE, &isect, NULL, 0.0f, 0.0f);
#else
bool result = scene_intersect(kg, ray, PATH_RAY_SHADOW_OPAQUE, &isect);
#endif
#ifdef __TRANSPARENT_SHADOWS__
if(result && kernel_data.integrator.transparent_shadows) {
/* transparent shadows work in such a way to try to minimize overhead
* in cases where we don't need them. after a regular shadow ray is
* cast we check if the hit primitive was potentially transparent, and
* only in that case start marching. this gives on extra ray cast for
* the cases were we do want transparency.
*
* also note that for this to work correct, multi close sampling must
* be used, since we don't pass a random number to shader_eval_surface */
if(shader_transparent_shadow(kg, &isect)) {
float3 throughput = make_float3(1.0f, 1.0f, 1.0f);
float3 Pend = ray->P + ray->D*ray->t;
int bounce = state->transparent_bounce;
for(;;) {
if(bounce >= kernel_data.integrator.transparent_max_bounce) {
return true;
}
else if(bounce >= kernel_data.integrator.transparent_min_bounce) {
/* todo: get random number somewhere for probabilistic terminate */
#if 0
float probability = average(throughput);
float terminate = 0.0f;
if(terminate >= probability)
return true;
throughput /= probability;
#endif
}
#ifdef __HAIR__
if(!scene_intersect(kg, ray, PATH_RAY_SHADOW_TRANSPARENT, &isect, NULL, 0.0f, 0.0f)) {
#else
if(!scene_intersect(kg, ray, PATH_RAY_SHADOW_TRANSPARENT, &isect)) {
#endif
*shadow *= throughput;
return false;
}
if(!shader_transparent_shadow(kg, &isect))
return true;
ShaderData sd;
shader_setup_from_ray(kg, &sd, &isect, ray, state->bounce+1);
shader_eval_surface(kg, &sd, 0.0f, PATH_RAY_SHADOW, SHADER_CONTEXT_SHADOW);
throughput *= shader_bsdf_transparency(kg, &sd);
ray->P = ray_offset(sd.P, -sd.Ng);
if(ray->t != FLT_MAX)
ray->D = normalize_len(Pend - ray->P, &ray->t);
bounce++;
}
}
}
#endif
return result;
}
#if defined(__BRANCHED_PATH__) || defined(__BSSRDF__)
__device void kernel_path_indirect(KernelGlobals *kg, RNG *rng, int sample, Ray ray, __global float *buffer,
float3 throughput, int num_samples, int num_total_samples,
float min_ray_pdf, float ray_pdf, PathState state, int rng_offset, PathRadiance *L)
{
#ifdef __LAMP_MIS__
float ray_t = 0.0f;
#endif
/* path iteration */
for(;; rng_offset += PRNG_BOUNCE_NUM) {
/* intersect scene */
Intersection isect;
uint visibility = path_state_ray_visibility(kg, &state);
#ifdef __HAIR__
bool hit = scene_intersect(kg, &ray, visibility, &isect, NULL, 0.0f, 0.0f);
#else
bool hit = scene_intersect(kg, &ray, visibility, &isect);
#endif
#ifdef __LAMP_MIS__
if(kernel_data.integrator.use_lamp_mis && !(state.flag & PATH_RAY_CAMERA)) {
/* ray starting from previous non-transparent bounce */
Ray light_ray;
light_ray.P = ray.P - ray_t*ray.D;
ray_t += isect.t;
light_ray.D = ray.D;
light_ray.t = ray_t;
light_ray.time = ray.time;
light_ray.dD = ray.dD;
light_ray.dP = ray.dP;
/* intersect with lamp */
float light_t = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT);
float3 emission;
if(indirect_lamp_emission(kg, &light_ray, state.flag, ray_pdf, light_t, &emission, state.bounce))
path_radiance_accum_emission(L, throughput, emission, state.bounce);
}
#endif
if(!hit) {
#ifdef __BACKGROUND__
/* sample background shader */
float3 L_background = indirect_background(kg, &ray, state.flag, ray_pdf, state.bounce);
path_radiance_accum_background(L, throughput, L_background, state.bounce);
#endif
break;
}
/* setup shading */
ShaderData sd;
shader_setup_from_ray(kg, &sd, &isect, &ray, state.bounce);
float rbsdf = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_BSDF);
shader_eval_surface(kg, &sd, rbsdf, state.flag, SHADER_CONTEXT_INDIRECT);
shader_merge_closures(kg, &sd);
/* blurring of bsdf after bounces, for rays that have a small likelihood
* of following this particular path (diffuse, rough glossy) */
if(kernel_data.integrator.filter_glossy != FLT_MAX) {
float blur_pdf = kernel_data.integrator.filter_glossy*min_ray_pdf;
if(blur_pdf < 1.0f) {
float blur_roughness = sqrtf(1.0f - blur_pdf)*0.5f;
shader_bsdf_blur(kg, &sd, blur_roughness);
}
}
#ifdef __EMISSION__
/* emission */
if(sd.flag & SD_EMISSION) {
float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, ray_pdf);
path_radiance_accum_emission(L, throughput, emission, state.bounce);
}
#endif
/* path termination. this is a strange place to put the termination, it's
* mainly due to the mixed in MIS that we use. gives too many unneeded
* shader evaluations, only need emission if we are going to terminate */
float probability = path_state_terminate_probability(kg, &state, throughput*num_samples);
if(probability == 0.0f) {
break;
}
else if(probability != 1.0f) {
float terminate = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_TERMINATE);
if(terminate >= probability)
break;
throughput /= probability;
}
#ifdef __AO__
/* ambient occlusion */
if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
float bsdf_u, bsdf_v;
path_rng_2D(kg, rng, sample, num_total_samples, rng_offset + PRNG_BSDF_U, &bsdf_u, &bsdf_v);
float ao_factor = kernel_data.background.ao_factor;
float3 ao_N;
float3 ao_bsdf = shader_bsdf_ao(kg, &sd, ao_factor, &ao_N);
float3 ao_D;
float ao_pdf;
sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
if(dot(sd.Ng, ao_D) > 0.0f && ao_pdf != 0.0f) {
Ray light_ray;
float3 ao_shadow;
light_ray.P = ray_offset(sd.P, sd.Ng);
light_ray.D = ao_D;
light_ray.t = kernel_data.background.ao_distance;
#ifdef __OBJECT_MOTION__
light_ray.time = sd.time;
#endif
light_ray.dP = sd.dP;
light_ray.dD = differential3_zero();
if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow))
path_radiance_accum_ao(L, throughput, ao_bsdf, ao_shadow, state.bounce);
}
}
#endif
#ifdef __SUBSURFACE__
/* bssrdf scatter to a different location on the same object, replacing
* the closures with a diffuse BSDF */
if(sd.flag & SD_BSSRDF) {
float bssrdf_probability;
ShaderClosure *sc = subsurface_scatter_pick_closure(kg, &sd, &bssrdf_probability);
/* modify throughput for picking bssrdf or bsdf */
throughput *= bssrdf_probability;
/* do bssrdf scatter step if we picked a bssrdf closure */
if(sc) {
uint lcg_state = lcg_init(*rng + rng_offset + sample*0x68bc21eb);
if(old_subsurface_scatter_use(&sd)) {
old_subsurface_scatter_step(kg, &sd, state.flag, sc, &lcg_state, false);
}
else {
float bssrdf_u, bssrdf_v;
path_rng_2D(kg, rng, sample, num_total_samples, rng_offset + PRNG_BSDF_U, &bssrdf_u, &bssrdf_v);
subsurface_scatter_step(kg, &sd, state.flag, sc, &lcg_state, bssrdf_u, bssrdf_v, false);
}
state.flag |= PATH_RAY_BSSRDF_ANCESTOR;
}
}
#endif
#ifdef __EMISSION__
if(kernel_data.integrator.use_direct_light) {
/* sample illumination from lights to find path contribution */
if(sd.flag & SD_BSDF_HAS_EVAL) {
float light_t = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT);
#ifdef __MULTI_CLOSURE__
float light_o = 0.0f;
#else
float light_o = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT_F);
#endif
float light_u, light_v;
path_rng_2D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT_U, &light_u, &light_v);
Ray light_ray;
BsdfEval L_light;
bool is_lamp;
#ifdef __OBJECT_MOTION__
light_ray.time = sd.time;
#endif
/* sample random light */
if(direct_emission(kg, &sd, -1, light_t, light_o, light_u, light_v, &light_ray, &L_light, &is_lamp, state.bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(L, throughput, &L_light, shadow, 1.0f, state.bounce, is_lamp);
}
}
}
}
#endif
/* no BSDF? we can stop here */
if(!(sd.flag & SD_BSDF))
break;
/* sample BSDF */
float bsdf_pdf;
BsdfEval bsdf_eval;
float3 bsdf_omega_in;
differential3 bsdf_domega_in;
float bsdf_u, bsdf_v;
path_rng_2D(kg, rng, sample, num_total_samples, rng_offset + PRNG_BSDF_U, &bsdf_u, &bsdf_v);
int label;
label = shader_bsdf_sample(kg, &sd, bsdf_u, bsdf_v, &bsdf_eval,
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
break;
/* modify throughput */
path_radiance_bsdf_bounce(L, &throughput, &bsdf_eval, bsdf_pdf, state.bounce, label);
/* set labels */
if(!(label & LABEL_TRANSPARENT)) {
ray_pdf = bsdf_pdf;
#ifdef __LAMP_MIS__
ray_t = 0.0f;
#endif
min_ray_pdf = fminf(bsdf_pdf, min_ray_pdf);
}
/* update path state */
path_state_next(kg, &state, label);
/* setup ray */
ray.P = ray_offset(sd.P, (label & LABEL_TRANSMIT)? -sd.Ng: sd.Ng);
ray.D = bsdf_omega_in;
ray.t = FLT_MAX;
#ifdef __RAY_DIFFERENTIALS__
ray.dP = sd.dP;
ray.dD = bsdf_domega_in;
#endif
}
}
#endif
#ifdef __SUBSURFACE__
__device_inline bool kernel_path_integrate_lighting(KernelGlobals *kg, RNG *rng,
int sample, int num_samples,
ShaderData *sd, float3 *throughput,
float *min_ray_pdf, float *ray_pdf, PathState *state,
int rng_offset, PathRadiance *L, Ray *ray, float *ray_t)
{
#ifdef __EMISSION__
if(kernel_data.integrator.use_direct_light) {
/* sample illumination from lights to find path contribution */
if(sd->flag & SD_BSDF_HAS_EVAL) {
float light_t = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT);
#ifdef __MULTI_CLOSURE__
float light_o = 0.0f;
#else
float light_o = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT_F);
#endif
float light_u, light_v;
path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT_U, &light_u, &light_v);
Ray light_ray;
BsdfEval L_light;
bool is_lamp;
#ifdef __OBJECT_MOTION__
light_ray.time = sd->time;
#endif
if(direct_emission(kg, sd, -1, light_t, light_o, light_u, light_v, &light_ray, &L_light, &is_lamp, state->bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(L, *throughput, &L_light, shadow, 1.0f, state->bounce, is_lamp);
}
}
}
}
#endif
/* no BSDF? we can stop here */
if(!(sd->flag & SD_BSDF))
return false;
/* sample BSDF */
float bsdf_pdf;
BsdfEval bsdf_eval;
float3 bsdf_omega_in;
differential3 bsdf_domega_in;
float bsdf_u, bsdf_v;
path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF_U, &bsdf_u, &bsdf_v);
int label;
label = shader_bsdf_sample(kg, sd, bsdf_u, bsdf_v, &bsdf_eval,
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
return false;
/* modify throughput */
path_radiance_bsdf_bounce(L, throughput, &bsdf_eval, bsdf_pdf, state->bounce, label);
/* set labels */
if(!(label & LABEL_TRANSPARENT)) {
*ray_pdf = bsdf_pdf;
#ifdef __LAMP_MIS__
*ray_t = 0.0f;
#endif
*min_ray_pdf = fminf(bsdf_pdf, *min_ray_pdf);
}
/* update path state */
path_state_next(kg, state, label);
/* setup ray */
ray->P = ray_offset(sd->P, (label & LABEL_TRANSMIT)? -sd->Ng: sd->Ng);
ray->D = bsdf_omega_in;
if(state->bounce == 0)
ray->t -= sd->ray_length; /* clipping works through transparent */
else
ray->t = FLT_MAX;
#ifdef __RAY_DIFFERENTIALS__
ray->dP = sd->dP;
ray->dD = bsdf_domega_in;
#endif
return true;
}
#endif
__device float4 kernel_path_integrate(KernelGlobals *kg, RNG *rng, int sample, Ray ray, __global float *buffer)
{
/* initialize */
PathRadiance L;
float3 throughput = make_float3(1.0f, 1.0f, 1.0f);
float L_transparent = 0.0f;
path_radiance_init(&L, kernel_data.film.use_light_pass);
float min_ray_pdf = FLT_MAX;
float ray_pdf = 0.0f;
float ray_t = 0.0f;
PathState state;
int rng_offset = PRNG_BASE_NUM;
#ifdef __CMJ__
int num_samples = kernel_data.integrator.aa_samples;
#else
int num_samples = 0;
#endif
path_state_init(&state);
/* path iteration */
for(;; rng_offset += PRNG_BOUNCE_NUM) {
/* intersect scene */
Intersection isect;
uint visibility = path_state_ray_visibility(kg, &state);
#ifdef __HAIR__
float difl = 0.0f, extmax = 0.0f;
uint lcg_state = 0;
if(kernel_data.bvh.have_curves) {
if((kernel_data.cam.resolution == 1) && (state.flag & PATH_RAY_CAMERA)) {
float3 pixdiff = ray.dD.dx + ray.dD.dy;
/*pixdiff = pixdiff - dot(pixdiff, ray.D)*ray.D;*/
difl = kernel_data.curve.minimum_width * len(pixdiff) * 0.5f;
}
extmax = kernel_data.curve.maximum_width;
lcg_state = lcg_init(*rng + rng_offset + sample*0x51633e2d);
}
bool hit = scene_intersect(kg, &ray, visibility, &isect, &lcg_state, difl, extmax);
#else
bool hit = scene_intersect(kg, &ray, visibility, &isect);
#endif
#ifdef __LAMP_MIS__
if(kernel_data.integrator.use_lamp_mis && !(state.flag & PATH_RAY_CAMERA)) {
/* ray starting from previous non-transparent bounce */
Ray light_ray;
light_ray.P = ray.P - ray_t*ray.D;
ray_t += isect.t;
light_ray.D = ray.D;
light_ray.t = ray_t;
light_ray.time = ray.time;
light_ray.dD = ray.dD;
light_ray.dP = ray.dP;
/* intersect with lamp */
float light_t = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT);
float3 emission;
if(indirect_lamp_emission(kg, &light_ray, state.flag, ray_pdf, light_t, &emission, state.bounce))
path_radiance_accum_emission(&L, throughput, emission, state.bounce);
}
#endif
if(!hit) {
/* eval background shader if nothing hit */
if(kernel_data.background.transparent && (state.flag & PATH_RAY_CAMERA)) {
L_transparent += average(throughput);
#ifdef __PASSES__
if(!(kernel_data.film.pass_flag & PASS_BACKGROUND))
#endif
break;
}
#ifdef __BACKGROUND__
/* sample background shader */
float3 L_background = indirect_background(kg, &ray, state.flag, ray_pdf, state.bounce);
path_radiance_accum_background(&L, throughput, L_background, state.bounce);
#endif
break;
}
/* setup shading */
ShaderData sd;
shader_setup_from_ray(kg, &sd, &isect, &ray, state.bounce);
float rbsdf = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF);
shader_eval_surface(kg, &sd, rbsdf, state.flag, SHADER_CONTEXT_MAIN);
/* holdout */
#ifdef __HOLDOUT__
if((sd.flag & (SD_HOLDOUT|SD_HOLDOUT_MASK)) && (state.flag & PATH_RAY_CAMERA)) {
if(kernel_data.background.transparent) {
float3 holdout_weight;
if(sd.flag & SD_HOLDOUT_MASK)
holdout_weight = make_float3(1.0f, 1.0f, 1.0f);
else
holdout_weight = shader_holdout_eval(kg, &sd);
/* any throughput is ok, should all be identical here */
L_transparent += average(holdout_weight*throughput);
}
if(sd.flag & SD_HOLDOUT_MASK)
break;
}
#endif
/* holdout mask objects do not write data passes */
kernel_write_data_passes(kg, buffer, &L, &sd, sample, state.flag, throughput);
/* blurring of bsdf after bounces, for rays that have a small likelihood
* of following this particular path (diffuse, rough glossy) */
if(kernel_data.integrator.filter_glossy != FLT_MAX) {
float blur_pdf = kernel_data.integrator.filter_glossy*min_ray_pdf;
if(blur_pdf < 1.0f) {
float blur_roughness = sqrtf(1.0f - blur_pdf)*0.5f;
shader_bsdf_blur(kg, &sd, blur_roughness);
}
}
#ifdef __EMISSION__
/* emission */
if(sd.flag & SD_EMISSION) {
/* todo: is isect.t wrong here for transparent surfaces? */
float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, ray_pdf);
path_radiance_accum_emission(&L, throughput, emission, state.bounce);
}
#endif
/* path termination. this is a strange place to put the termination, it's
* mainly due to the mixed in MIS that we use. gives too many unneeded
* shader evaluations, only need emission if we are going to terminate */
float probability = path_state_terminate_probability(kg, &state, throughput);
if(probability == 0.0f) {
break;
}
else if(probability != 1.0f) {
float terminate = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_TERMINATE);
if(terminate >= probability)
break;
throughput /= probability;
}
#ifdef __AO__
/* ambient occlusion */
if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
/* todo: solve correlation */
float bsdf_u, bsdf_v;
path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF_U, &bsdf_u, &bsdf_v);
float ao_factor = kernel_data.background.ao_factor;
float3 ao_N;
float3 ao_bsdf = shader_bsdf_ao(kg, &sd, ao_factor, &ao_N);
float3 ao_D;
float ao_pdf;
sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
if(dot(sd.Ng, ao_D) > 0.0f && ao_pdf != 0.0f) {
Ray light_ray;
float3 ao_shadow;
light_ray.P = ray_offset(sd.P, sd.Ng);
light_ray.D = ao_D;
light_ray.t = kernel_data.background.ao_distance;
#ifdef __OBJECT_MOTION__
light_ray.time = sd.time;
#endif
light_ray.dP = sd.dP;
light_ray.dD = differential3_zero();
if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow))
path_radiance_accum_ao(&L, throughput, ao_bsdf, ao_shadow, state.bounce);
}
}
#endif
#ifdef __SUBSURFACE__
/* bssrdf scatter to a different location on the same object, replacing
* the closures with a diffuse BSDF */
if(sd.flag & SD_BSSRDF) {
float bssrdf_probability;
ShaderClosure *sc = subsurface_scatter_pick_closure(kg, &sd, &bssrdf_probability);
/* modify throughput for picking bssrdf or bsdf */
throughput *= bssrdf_probability;
/* do bssrdf scatter step if we picked a bssrdf closure */
if(sc) {
uint lcg_state = lcg_init(*rng + rng_offset + sample*0x68bc21eb);
if(old_subsurface_scatter_use(&sd)) {
old_subsurface_scatter_step(kg, &sd, state.flag, sc, &lcg_state, false);
}
else {
ShaderData bssrdf_sd[BSSRDF_MAX_HITS];
float bssrdf_u, bssrdf_v;
path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF_U, &bssrdf_u, &bssrdf_v);
int num_hits = subsurface_scatter_multi_step(kg, &sd, bssrdf_sd, state.flag, sc, &lcg_state, bssrdf_u, bssrdf_v, false);
/* compute lighting with the BSDF closure */
for(int hit = 0; hit < num_hits; hit++) {
float3 tp = throughput;
PathState hit_state = state;
Ray hit_ray = ray;
float hit_ray_t = ray_t;
float hit_ray_pdf = ray_pdf;
float hit_min_ray_pdf = min_ray_pdf;
hit_state.flag |= PATH_RAY_BSSRDF_ANCESTOR;
if(kernel_path_integrate_lighting(kg, rng, sample, num_samples, &bssrdf_sd[hit],
&tp, &hit_min_ray_pdf, &hit_ray_pdf, &hit_state, rng_offset+PRNG_BOUNCE_NUM, &L, &hit_ray, &hit_ray_t)) {
kernel_path_indirect(kg, rng, sample, hit_ray, buffer,
tp, num_samples, num_samples,
hit_min_ray_pdf, hit_ray_pdf, hit_state, rng_offset+PRNG_BOUNCE_NUM*2, &L);
/* for render passes, sum and reset indirect light pass variables
* for the next samples */
path_radiance_sum_indirect(&L);
path_radiance_reset_indirect(&L);
}
}
break;
}
}
}
#endif
/* The following code is the same as in kernel_path_integrate_lighting(),
but for CUDA the function call is slower. */
#ifdef __EMISSION__
if(kernel_data.integrator.use_direct_light) {
/* sample illumination from lights to find path contribution */
if(sd.flag & SD_BSDF_HAS_EVAL) {
float light_t = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT);
#ifdef __MULTI_CLOSURE__
float light_o = 0.0f;
#else
float light_o = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT_F);
#endif
float light_u, light_v;
path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT_U, &light_u, &light_v);
Ray light_ray;
BsdfEval L_light;
bool is_lamp;
#ifdef __OBJECT_MOTION__
light_ray.time = sd.time;
#endif
if(direct_emission(kg, &sd, -1, light_t, light_o, light_u, light_v, &light_ray, &L_light, &is_lamp, state.bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(&L, throughput, &L_light, shadow, 1.0f, state.bounce, is_lamp);
}
}
}
}
#endif
/* no BSDF? we can stop here */
if(!(sd.flag & SD_BSDF))
break;
/* sample BSDF */
float bsdf_pdf;
BsdfEval bsdf_eval;
float3 bsdf_omega_in;
differential3 bsdf_domega_in;
float bsdf_u, bsdf_v;
path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF_U, &bsdf_u, &bsdf_v);
int label;
label = shader_bsdf_sample(kg, &sd, bsdf_u, bsdf_v, &bsdf_eval,
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
break;
/* modify throughput */
path_radiance_bsdf_bounce(&L, &throughput, &bsdf_eval, bsdf_pdf, state.bounce, label);
/* set labels */
if(!(label & LABEL_TRANSPARENT)) {
ray_pdf = bsdf_pdf;
#ifdef __LAMP_MIS__
ray_t = 0.0f;
#endif
min_ray_pdf = fminf(bsdf_pdf, min_ray_pdf);
}
/* update path state */
path_state_next(kg, &state, label);
/* setup ray */
ray.P = ray_offset(sd.P, (label & LABEL_TRANSMIT)? -sd.Ng: sd.Ng);
ray.D = bsdf_omega_in;
if(state.bounce == 0)
ray.t -= sd.ray_length; /* clipping works through transparent */
else
ray.t = FLT_MAX;
#ifdef __RAY_DIFFERENTIALS__
ray.dP = sd.dP;
ray.dD = bsdf_domega_in;
#endif
}
float3 L_sum = path_radiance_sum(kg, &L);
#ifdef __CLAMP_SAMPLE__
path_radiance_clamp(&L, &L_sum, kernel_data.integrator.sample_clamp);
#endif
kernel_write_light_passes(kg, buffer, &L, sample);
return make_float4(L_sum.x, L_sum.y, L_sum.z, 1.0f - L_transparent);
}
#ifdef __BRANCHED_PATH__
__device_noinline void kernel_branched_path_integrate_lighting(KernelGlobals *kg, RNG *rng,
int sample, int aa_samples,
ShaderData *sd, float3 throughput, float num_samples_adjust,
float min_ray_pdf, float ray_pdf, PathState state,
int rng_offset, PathRadiance *L, __global float *buffer)
{
#ifdef __EMISSION__
/* sample illumination from lights to find path contribution */
if(sd->flag & SD_BSDF_HAS_EVAL) {
Ray light_ray;
BsdfEval L_light;
bool is_lamp;
#ifdef __OBJECT_MOTION__
light_ray.time = sd->time;
#endif
/* lamp sampling */
for(int i = 0; i < kernel_data.integrator.num_all_lights; i++) {
int num_samples = ceil_to_int(num_samples_adjust*light_select_num_samples(kg, i));
float num_samples_inv = num_samples_adjust/(num_samples*kernel_data.integrator.num_all_lights);
RNG lamp_rng = cmj_hash(*rng, i);
if(kernel_data.integrator.pdf_triangles != 0.0f)
num_samples_inv *= 0.5f;
for(int j = 0; j < num_samples; j++) {
float light_u, light_v;
path_rng_2D(kg, &lamp_rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_LIGHT_U, &light_u, &light_v);
if(direct_emission(kg, sd, i, 0.0f, 0.0f, light_u, light_v, &light_ray, &L_light, &is_lamp, state.bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(L, throughput*num_samples_inv, &L_light, shadow, num_samples_inv, state.bounce, is_lamp);
}
}
}
}
/* mesh light sampling */
if(kernel_data.integrator.pdf_triangles != 0.0f) {
int num_samples = ceil_to_int(num_samples_adjust*kernel_data.integrator.mesh_light_samples);
float num_samples_inv = num_samples_adjust/num_samples;
if(kernel_data.integrator.num_all_lights)
num_samples_inv *= 0.5f;
for(int j = 0; j < num_samples; j++) {
float light_t = path_rng_1D(kg, rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_LIGHT);
float light_u, light_v;
path_rng_2D(kg, rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_LIGHT_U, &light_u, &light_v);
/* only sample triangle lights */
if(kernel_data.integrator.num_all_lights)
light_t = 0.5f*light_t;
if(direct_emission(kg, sd, -1, light_t, 0.0f, light_u, light_v, &light_ray, &L_light, &is_lamp, state.bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(L, throughput*num_samples_inv, &L_light, shadow, num_samples_inv, state.bounce, is_lamp);
}
}
}
}
}
#endif
for(int i = 0; i< sd->num_closure; i++) {
const ShaderClosure *sc = &sd->closure[i];
if(!CLOSURE_IS_BSDF(sc->type))
continue;
/* transparency is not handled here, but in outer loop */
if(sc->type == CLOSURE_BSDF_TRANSPARENT_ID)
continue;
int num_samples;
if(CLOSURE_IS_BSDF_DIFFUSE(sc->type))
num_samples = kernel_data.integrator.diffuse_samples;
else if(CLOSURE_IS_BSDF_BSSRDF(sc->type))
num_samples = 1;
else if(CLOSURE_IS_BSDF_GLOSSY(sc->type))
num_samples = kernel_data.integrator.glossy_samples;
else
num_samples = kernel_data.integrator.transmission_samples;
num_samples = ceil_to_int(num_samples_adjust*num_samples);
float num_samples_inv = num_samples_adjust/num_samples;
RNG bsdf_rng = cmj_hash(*rng, i);
for(int j = 0; j < num_samples; j++) {
/* sample BSDF */
float bsdf_pdf;
BsdfEval bsdf_eval;
float3 bsdf_omega_in;
differential3 bsdf_domega_in;
float bsdf_u, bsdf_v;
path_rng_2D(kg, &bsdf_rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_BSDF_U, &bsdf_u, &bsdf_v);
int label;
label = shader_bsdf_sample_closure(kg, sd, sc, bsdf_u, bsdf_v, &bsdf_eval,
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
continue;
/* modify throughput */
float3 tp = throughput;
path_radiance_bsdf_bounce(L, &tp, &bsdf_eval, bsdf_pdf, state.bounce, label);
/* set labels */
float min_ray_pdf = fminf(bsdf_pdf, FLT_MAX);
/* modify path state */
PathState ps = state;
path_state_next(kg, &ps, label);
/* setup ray */
Ray bsdf_ray;
bsdf_ray.P = ray_offset(sd->P, (label & LABEL_TRANSMIT)? -sd->Ng: sd->Ng);
bsdf_ray.D = bsdf_omega_in;
bsdf_ray.t = FLT_MAX;
#ifdef __RAY_DIFFERENTIALS__
bsdf_ray.dP = sd->dP;
bsdf_ray.dD = bsdf_domega_in;
#endif
#ifdef __OBJECT_MOTION__
bsdf_ray.time = sd->time;
#endif
kernel_path_indirect(kg, rng, sample*num_samples + j, bsdf_ray, buffer,
tp*num_samples_inv, num_samples, aa_samples*num_samples,
min_ray_pdf, bsdf_pdf, ps, rng_offset+PRNG_BOUNCE_NUM, L);
/* for render passes, sum and reset indirect light pass variables
* for the next samples */
path_radiance_sum_indirect(L);
path_radiance_reset_indirect(L);
}
}
}
__device float4 kernel_branched_path_integrate(KernelGlobals *kg, RNG *rng, int sample, Ray ray, __global float *buffer)
{
/* initialize */
PathRadiance L;
float3 throughput = make_float3(1.0f, 1.0f, 1.0f);
float L_transparent = 0.0f;
path_radiance_init(&L, kernel_data.film.use_light_pass);
float ray_pdf = 0.0f;
PathState state;
int rng_offset = PRNG_BASE_NUM;
#ifdef __CMJ__
int aa_samples = kernel_data.integrator.aa_samples;
#else
int aa_samples = 0;
#endif
path_state_init(&state);
for(;; rng_offset += PRNG_BOUNCE_NUM) {
/* intersect scene */
Intersection isect;
uint visibility = path_state_ray_visibility(kg, &state);
#ifdef __HAIR__
float difl = 0.0f, extmax = 0.0f;
uint lcg_state = 0;
if(kernel_data.bvh.have_curves) {
if((kernel_data.cam.resolution == 1) && (state.flag & PATH_RAY_CAMERA)) {
float3 pixdiff = ray.dD.dx + ray.dD.dy;
/*pixdiff = pixdiff - dot(pixdiff, ray.D)*ray.D;*/
difl = kernel_data.curve.minimum_width * len(pixdiff) * 0.5f;
}
extmax = kernel_data.curve.maximum_width;
lcg_state = lcg_init(*rng + rng_offset + sample*0x51633e2d);
}
if(!scene_intersect(kg, &ray, visibility, &isect, &lcg_state, difl, extmax)) {
#else
if(!scene_intersect(kg, &ray, visibility, &isect)) {
#endif
/* eval background shader if nothing hit */
if(kernel_data.background.transparent) {
L_transparent += average(throughput);
#ifdef __PASSES__
if(!(kernel_data.film.pass_flag & PASS_BACKGROUND))
#endif
break;
}
#ifdef __BACKGROUND__
/* sample background shader */
float3 L_background = indirect_background(kg, &ray, state.flag, ray_pdf, state.bounce);
path_radiance_accum_background(&L, throughput, L_background, state.bounce);
#endif
break;
}
/* setup shading */
ShaderData sd;
shader_setup_from_ray(kg, &sd, &isect, &ray, state.bounce);
shader_eval_surface(kg, &sd, 0.0f, state.flag, SHADER_CONTEXT_MAIN);
shader_merge_closures(kg, &sd);
/* holdout */
#ifdef __HOLDOUT__
if((sd.flag & (SD_HOLDOUT|SD_HOLDOUT_MASK))) {
if(kernel_data.background.transparent) {
float3 holdout_weight;
if(sd.flag & SD_HOLDOUT_MASK)
holdout_weight = make_float3(1.0f, 1.0f, 1.0f);
else
holdout_weight = shader_holdout_eval(kg, &sd);
/* any throughput is ok, should all be identical here */
L_transparent += average(holdout_weight*throughput);
}
if(sd.flag & SD_HOLDOUT_MASK)
break;
}
#endif
/* holdout mask objects do not write data passes */
kernel_write_data_passes(kg, buffer, &L, &sd, sample, state.flag, throughput);
#ifdef __EMISSION__
/* emission */
if(sd.flag & SD_EMISSION) {
float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, ray_pdf);
path_radiance_accum_emission(&L, throughput, emission, state.bounce);
}
#endif
/* transparency termination */
if(state.flag & PATH_RAY_TRANSPARENT) {
/* path termination. this is a strange place to put the termination, it's
* mainly due to the mixed in MIS that we use. gives too many unneeded
* shader evaluations, only need emission if we are going to terminate */
float probability = path_state_terminate_probability(kg, &state, throughput);
if(probability == 0.0f) {
break;
}
else if(probability != 1.0f) {
float terminate = path_rng_1D(kg, rng, sample, aa_samples, rng_offset + PRNG_TERMINATE);
if(terminate >= probability)
break;
throughput /= probability;
}
}
#ifdef __AO__
/* ambient occlusion */
if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
int num_samples = kernel_data.integrator.ao_samples;
float num_samples_inv = 1.0f/num_samples;
float ao_factor = kernel_data.background.ao_factor;
float3 ao_N;
float3 ao_bsdf = shader_bsdf_ao(kg, &sd, ao_factor, &ao_N);
for(int j = 0; j < num_samples; j++) {
float bsdf_u, bsdf_v;
path_rng_2D(kg, rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_BSDF_U, &bsdf_u, &bsdf_v);
float3 ao_D;
float ao_pdf;
sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
if(dot(sd.Ng, ao_D) > 0.0f && ao_pdf != 0.0f) {
Ray light_ray;
float3 ao_shadow;
light_ray.P = ray_offset(sd.P, sd.Ng);
light_ray.D = ao_D;
light_ray.t = kernel_data.background.ao_distance;
#ifdef __OBJECT_MOTION__
light_ray.time = sd.time;
#endif
light_ray.dP = sd.dP;
light_ray.dD = differential3_zero();
if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow))
path_radiance_accum_ao(&L, throughput*num_samples_inv, ao_bsdf, ao_shadow, state.bounce);
}
}
}
#endif
#ifdef __SUBSURFACE__
/* bssrdf scatter to a different location on the same object */
if(sd.flag & SD_BSSRDF) {
for(int i = 0; i< sd.num_closure; i++) {
ShaderClosure *sc = &sd.closure[i];
if(!CLOSURE_IS_BSSRDF(sc->type))
continue;
/* set up random number generator */
uint lcg_state = lcg_init(*rng + rng_offset + sample*0x68bc21eb);
int num_samples = kernel_data.integrator.subsurface_samples;
float num_samples_inv = 1.0f/num_samples;
RNG bssrdf_rng = cmj_hash(*rng, i);
state.flag |= PATH_RAY_BSSRDF_ANCESTOR;
/* do subsurface scatter step with copy of shader data, this will
* replace the BSSRDF with a diffuse BSDF closure */
for(int j = 0; j < num_samples; j++) {
if(old_subsurface_scatter_use(&sd)) {
ShaderData bssrdf_sd = sd;
old_subsurface_scatter_step(kg, &bssrdf_sd, state.flag, sc, &lcg_state, true);
/* compute lighting with the BSDF closure */
kernel_branched_path_integrate_lighting(kg, rng, sample*num_samples + j,
aa_samples*num_samples,
&bssrdf_sd, throughput, num_samples_inv,
ray_pdf, ray_pdf, state, rng_offset, &L, buffer);
}
else {
ShaderData bssrdf_sd[BSSRDF_MAX_HITS];
float bssrdf_u, bssrdf_v;
path_rng_2D(kg, &bssrdf_rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_BSDF_U, &bssrdf_u, &bssrdf_v);
int num_hits = subsurface_scatter_multi_step(kg, &sd, bssrdf_sd, state.flag, sc, &lcg_state, bssrdf_u, bssrdf_v, true);
/* compute lighting with the BSDF closure */
for(int hit = 0; hit < num_hits; hit++)
kernel_branched_path_integrate_lighting(kg, rng, sample*num_samples + j,
aa_samples*num_samples,
&bssrdf_sd[hit], throughput, num_samples_inv,
ray_pdf, ray_pdf, state, rng_offset+PRNG_BOUNCE_NUM, &L, buffer);
}
}
state.flag &= ~PATH_RAY_BSSRDF_ANCESTOR;
}
}
#endif
/* lighting */
kernel_branched_path_integrate_lighting(kg, rng, sample, aa_samples,
&sd, throughput, 1.0f, ray_pdf, ray_pdf, state, rng_offset, &L, buffer);
/* continue in case of transparency */
throughput *= shader_bsdf_transparency(kg, &sd);
if(is_zero(throughput))
break;
path_state_next(kg, &state, LABEL_TRANSPARENT);
ray.P = ray_offset(sd.P, -sd.Ng);
ray.t -= sd.ray_length; /* clipping works through transparent */
}
float3 L_sum = path_radiance_sum(kg, &L);
#ifdef __CLAMP_SAMPLE__
path_radiance_clamp(&L, &L_sum, kernel_data.integrator.sample_clamp);
#endif
kernel_write_light_passes(kg, buffer, &L, sample);
return make_float4(L_sum.x, L_sum.y, L_sum.z, 1.0f - L_transparent);
}
#endif
__device_inline void kernel_path_trace_setup(KernelGlobals *kg, __global uint *rng_state, int sample, int x, int y, RNG *rng, Ray *ray)
{
float filter_u;
float filter_v;
#ifdef __CMJ__
int num_samples = kernel_data.integrator.aa_samples;
#else
int num_samples = 0;
#endif
path_rng_init(kg, rng_state, sample, num_samples, rng, x, y, &filter_u, &filter_v);
/* sample camera ray */
float lens_u = 0.0f, lens_v = 0.0f;
if(kernel_data.cam.aperturesize > 0.0f)
path_rng_2D(kg, rng, sample, num_samples, PRNG_LENS_U, &lens_u, &lens_v);
float time = 0.0f;
#ifdef __CAMERA_MOTION__
if(kernel_data.cam.shuttertime != -1.0f)
time = path_rng_1D(kg, rng, sample, num_samples, PRNG_TIME);
#endif
camera_sample(kg, x, y, filter_u, filter_v, lens_u, lens_v, time, ray);
}
__device void kernel_path_trace(KernelGlobals *kg,
__global float *buffer, __global uint *rng_state,
int sample, int x, int y, int offset, int stride)
{
/* buffer offset */
int index = offset + x + y*stride;
int pass_stride = kernel_data.film.pass_stride;
rng_state += index;
buffer += index*pass_stride;
/* initialize random numbers and ray */
RNG rng;
Ray ray;
kernel_path_trace_setup(kg, rng_state, sample, x, y, &rng, &ray);
/* integrate */
float4 L;
if (ray.t != 0.0f)
L = kernel_path_integrate(kg, &rng, sample, ray, buffer);
else
L = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
/* accumulate result in output buffer */
kernel_write_pass_float4(buffer, sample, L);
path_rng_end(kg, rng_state, rng);
}
#ifdef __BRANCHED_PATH__
__device void kernel_branched_path_trace(KernelGlobals *kg,
__global float *buffer, __global uint *rng_state,
int sample, int x, int y, int offset, int stride)
{
/* buffer offset */
int index = offset + x + y*stride;
int pass_stride = kernel_data.film.pass_stride;
rng_state += index;
buffer += index*pass_stride;
/* initialize random numbers and ray */
RNG rng;
Ray ray;
kernel_path_trace_setup(kg, rng_state, sample, x, y, &rng, &ray);
/* integrate */
float4 L;
if (ray.t != 0.0f)
L = kernel_branched_path_integrate(kg, &rng, sample, ray, buffer);
else
L = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
/* accumulate result in output buffer */
kernel_write_pass_float4(buffer, sample, L);
path_rng_end(kg, rng_state, rng);
}
#endif
CCL_NAMESPACE_END