blender/intern/cycles/kernel/kernel_path.h

1400 lines
40 KiB
C
Raw Normal View History

/*
* 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
2012-06-09 17:22:52 +00:00
* 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
2012-06-09 17:22:52 +00:00
* 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__
Cycles: merging features from tomato branch. === BVH build time optimizations === * BVH building was multithreaded. Not all building is multithreaded, packing and the initial bounding/splitting is still single threaded, but recursive splitting is, which was the main bottleneck. * Object splitting now uses binning rather than sorting of all elements, using code from the Embree raytracer from Intel. http://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels/ * Other small changes to avoid allocations, pack memory more tightly, avoid some unnecessary operations, ... These optimizations do not work yet when Spatial Splits are enabled, for that more work is needed. There's also other optimizations still needed, in particular for the case of many low poly objects, the packing step and node memory allocation. BVH raytracing time should remain about the same, but BVH build time should be significantly reduced, test here show speedup of about 5x to 10x on a dual core and 5x to 25x on an 8-core machine, depending on the scene. === Threads === Centralized task scheduler for multithreading, which is basically the CPU device threading code wrapped into something reusable. Basic idea is that there is a single TaskScheduler that keeps a pool of threads, one for each core. Other places in the code can then create a TaskPool that they can drop Tasks in to be executed by the scheduler, and wait for them to complete or cancel them early. === Normal ==== Added a Normal output to the texture coordinate node. This currently gives the object space normal, which is the same under object animation. In the future this might become a "generated" normal so it's also stable for deforming objects, but for now it's already useful for non-deforming objects. === Render Layers === Per render layer Samples control, leaving it to 0 will use the common scene setting. Environment pass will now render environment even if film is set to transparent. Exclude Layers" added. Scene layers (all object that influence the render, directly or indirectly) are shared between all render layers. However sometimes it's useful to leave out some object influence for a particular render layer. That's what this option allows you to do. === Filter Glossy === When using a value higher than 0.0, this will blur glossy reflections after blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good starting value to tweak. Some light paths have a low probability of being found while contributing much light to the pixel. As a result these light paths will be found in some pixels and not in others, causing fireflies. An example of such a difficult path might be a small light that is causing a small specular highlight on a sharp glossy material, which we are seeing through a rough glossy material. With path tracing it is difficult to find the specular highlight, but if we increase the roughness on the material the highlight gets bigger and softer, and so easier to find. Often this blurring will be hardly noticeable, because we are seeing it through a blurry material anyway, but there are also cases where this will lead to a loss of detail in lighting.
2012-04-28 08:53:59 +00:00
/* 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
2012-06-09 17:22:52 +00:00
* 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
#ifdef __SUBSURFACE__
if(!kernel_path_integrate_lighting(kg, rng, sample, num_samples, &sd,
&throughput, &min_ray_pdf, &ray_pdf, &state, rng_offset, &L, &ray, &ray_t))
break;
#else
#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 */
Cycles: merging features from tomato branch. === BVH build time optimizations === * BVH building was multithreaded. Not all building is multithreaded, packing and the initial bounding/splitting is still single threaded, but recursive splitting is, which was the main bottleneck. * Object splitting now uses binning rather than sorting of all elements, using code from the Embree raytracer from Intel. http://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels/ * Other small changes to avoid allocations, pack memory more tightly, avoid some unnecessary operations, ... These optimizations do not work yet when Spatial Splits are enabled, for that more work is needed. There's also other optimizations still needed, in particular for the case of many low poly objects, the packing step and node memory allocation. BVH raytracing time should remain about the same, but BVH build time should be significantly reduced, test here show speedup of about 5x to 10x on a dual core and 5x to 25x on an 8-core machine, depending on the scene. === Threads === Centralized task scheduler for multithreading, which is basically the CPU device threading code wrapped into something reusable. Basic idea is that there is a single TaskScheduler that keeps a pool of threads, one for each core. Other places in the code can then create a TaskPool that they can drop Tasks in to be executed by the scheduler, and wait for them to complete or cancel them early. === Normal ==== Added a Normal output to the texture coordinate node. This currently gives the object space normal, which is the same under object animation. In the future this might become a "generated" normal so it's also stable for deforming objects, but for now it's already useful for non-deforming objects. === Render Layers === Per render layer Samples control, leaving it to 0 will use the common scene setting. Environment pass will now render environment even if film is set to transparent. Exclude Layers" added. Scene layers (all object that influence the render, directly or indirectly) are shared between all render layers. However sometimes it's useful to leave out some object influence for a particular render layer. That's what this option allows you to do. === Filter Glossy === When using a value higher than 0.0, this will blur glossy reflections after blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good starting value to tweak. Some light paths have a low probability of being found while contributing much light to the pixel. As a result these light paths will be found in some pixels and not in others, causing fireflies. An example of such a difficult path might be a small light that is causing a small specular highlight on a sharp glossy material, which we are seeing through a rough glossy material. With path tracing it is difficult to find the specular highlight, but if we increase the roughness on the material the highlight gets bigger and softer, and so easier to find. Often this blurring will be hardly noticeable, because we are seeing it through a blurry material anyway, but there are also cases where this will lead to a loss of detail in lighting.
2012-04-28 08:53:59 +00:00
if(!(label & LABEL_TRANSPARENT)) {
ray_pdf = bsdf_pdf;
#ifdef __LAMP_MIS__
ray_t = 0.0f;
#endif
Cycles: merging features from tomato branch. === BVH build time optimizations === * BVH building was multithreaded. Not all building is multithreaded, packing and the initial bounding/splitting is still single threaded, but recursive splitting is, which was the main bottleneck. * Object splitting now uses binning rather than sorting of all elements, using code from the Embree raytracer from Intel. http://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels/ * Other small changes to avoid allocations, pack memory more tightly, avoid some unnecessary operations, ... These optimizations do not work yet when Spatial Splits are enabled, for that more work is needed. There's also other optimizations still needed, in particular for the case of many low poly objects, the packing step and node memory allocation. BVH raytracing time should remain about the same, but BVH build time should be significantly reduced, test here show speedup of about 5x to 10x on a dual core and 5x to 25x on an 8-core machine, depending on the scene. === Threads === Centralized task scheduler for multithreading, which is basically the CPU device threading code wrapped into something reusable. Basic idea is that there is a single TaskScheduler that keeps a pool of threads, one for each core. Other places in the code can then create a TaskPool that they can drop Tasks in to be executed by the scheduler, and wait for them to complete or cancel them early. === Normal ==== Added a Normal output to the texture coordinate node. This currently gives the object space normal, which is the same under object animation. In the future this might become a "generated" normal so it's also stable for deforming objects, but for now it's already useful for non-deforming objects. === Render Layers === Per render layer Samples control, leaving it to 0 will use the common scene setting. Environment pass will now render environment even if film is set to transparent. Exclude Layers" added. Scene layers (all object that influence the render, directly or indirectly) are shared between all render layers. However sometimes it's useful to leave out some object influence for a particular render layer. That's what this option allows you to do. === Filter Glossy === When using a value higher than 0.0, this will blur glossy reflections after blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good starting value to tweak. Some light paths have a low probability of being found while contributing much light to the pixel. As a result these light paths will be found in some pixels and not in others, causing fireflies. An example of such a difficult path might be a small light that is causing a small specular highlight on a sharp glossy material, which we are seeing through a rough glossy material. With path tracing it is difficult to find the specular highlight, but if we increase the roughness on the material the highlight gets bigger and softer, and so easier to find. Often this blurring will be hardly noticeable, because we are seeing it through a blurry material anyway, but there are also cases where this will lead to a loss of detail in lighting.
2012-04-28 08:53:59 +00:00
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
#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 */
}
Cycles: merging features from tomato branch. === BVH build time optimizations === * BVH building was multithreaded. Not all building is multithreaded, packing and the initial bounding/splitting is still single threaded, but recursive splitting is, which was the main bottleneck. * Object splitting now uses binning rather than sorting of all elements, using code from the Embree raytracer from Intel. http://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels/ * Other small changes to avoid allocations, pack memory more tightly, avoid some unnecessary operations, ... These optimizations do not work yet when Spatial Splits are enabled, for that more work is needed. There's also other optimizations still needed, in particular for the case of many low poly objects, the packing step and node memory allocation. BVH raytracing time should remain about the same, but BVH build time should be significantly reduced, test here show speedup of about 5x to 10x on a dual core and 5x to 25x on an 8-core machine, depending on the scene. === Threads === Centralized task scheduler for multithreading, which is basically the CPU device threading code wrapped into something reusable. Basic idea is that there is a single TaskScheduler that keeps a pool of threads, one for each core. Other places in the code can then create a TaskPool that they can drop Tasks in to be executed by the scheduler, and wait for them to complete or cancel them early. === Normal ==== Added a Normal output to the texture coordinate node. This currently gives the object space normal, which is the same under object animation. In the future this might become a "generated" normal so it's also stable for deforming objects, but for now it's already useful for non-deforming objects. === Render Layers === Per render layer Samples control, leaving it to 0 will use the common scene setting. Environment pass will now render environment even if film is set to transparent. Exclude Layers" added. Scene layers (all object that influence the render, directly or indirectly) are shared between all render layers. However sometimes it's useful to leave out some object influence for a particular render layer. That's what this option allows you to do. === Filter Glossy === When using a value higher than 0.0, this will blur glossy reflections after blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good starting value to tweak. Some light paths have a low probability of being found while contributing much light to the pixel. As a result these light paths will be found in some pixels and not in others, causing fireflies. An example of such a difficult path might be a small light that is causing a small specular highlight on a sharp glossy material, which we are seeing through a rough glossy material. With path tracing it is difficult to find the specular highlight, but if we increase the roughness on the material the highlight gets bigger and softer, and so easier to find. Often this blurring will be hardly noticeable, because we are seeing it through a blurry material anyway, but there are also cases where this will lead to a loss of detail in lighting.
2012-04-28 08:53:59 +00:00
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 */
Fisheye Camera for Cycles For sample images see: http://www.dalaifelinto.com/?p=399 (equisolid) http://www.dalaifelinto.com/?p=389 (equidistant) The 'use_panorama' option is now part of a new Camera type: 'Panorama'. Created two other panorama cameras: - Equisolid: most of lens in the market simulate this lens - e.g. Nikon, Canon, ...) this works as a real lens up to an extent. The final result takes the sensor dimensions into account also. .:. to simulate a Nikon DX2S with a 10.5mm lens do: sensor: 23.7 x 15.7 fisheye lens: 10.5 fisheye fov: 180 render dimensions: 4288 x 2848 - Equidistant: this is not a real lens model. Although the old equidistant lens simulate this lens. The result is always as a circular fisheye that takes the whole sensor (in other words, it doesn't take the sensor into consideration). This is perfect for fulldomes ;) For the UI we have 10 to 360 as soft values and 10 to 3600 as hard values (because we can). Reference material: http://www.hdrlabs.com/tutorials/downloads_files/HDRI%20for%20CGI.pdf http://www.bobatkins.com/photography/technical/field_of_view.html Note, this is not a real simulation of the light path through the lens. The ideal solution would be this: https://graphics.stanford.edu/wikis/cs348b-11/Assignment3 http://www.graphics.stanford.edu/papers/camera/ Thanks Brecht for the fix, suggestions and code review. Kudos for the dome community for keeping me stimulated on the topic since 2009 ;) Patch partly implemented during lab time at VisGraf, IMPA - Rio de Janeiro.
2012-05-04 16:20:51 +00:00
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);
Fisheye Camera for Cycles For sample images see: http://www.dalaifelinto.com/?p=399 (equisolid) http://www.dalaifelinto.com/?p=389 (equidistant) The 'use_panorama' option is now part of a new Camera type: 'Panorama'. Created two other panorama cameras: - Equisolid: most of lens in the market simulate this lens - e.g. Nikon, Canon, ...) this works as a real lens up to an extent. The final result takes the sensor dimensions into account also. .:. to simulate a Nikon DX2S with a 10.5mm lens do: sensor: 23.7 x 15.7 fisheye lens: 10.5 fisheye fov: 180 render dimensions: 4288 x 2848 - Equidistant: this is not a real lens model. Although the old equidistant lens simulate this lens. The result is always as a circular fisheye that takes the whole sensor (in other words, it doesn't take the sensor into consideration). This is perfect for fulldomes ;) For the UI we have 10 to 360 as soft values and 10 to 3600 as hard values (because we can). Reference material: http://www.hdrlabs.com/tutorials/downloads_files/HDRI%20for%20CGI.pdf http://www.bobatkins.com/photography/technical/field_of_view.html Note, this is not a real simulation of the light path through the lens. The ideal solution would be this: https://graphics.stanford.edu/wikis/cs348b-11/Assignment3 http://www.graphics.stanford.edu/papers/camera/ Thanks Brecht for the fix, suggestions and code review. Kudos for the dome community for keeping me stimulated on the topic since 2009 ;) Patch partly implemented during lab time at VisGraf, IMPA - Rio de Janeiro.
2012-05-04 16:20:51 +00:00
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