blender/intern/cycles/kernel/kernel_path_volume.h

263 lines
8.2 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
*/
CCL_NAMESPACE_BEGIN
#ifdef __VOLUME_SCATTER__
ccl_device void kernel_path_volume_connect_light(KernelGlobals *kg, RNG *rng,
ShaderData *sd, float3 throughput, PathState *state, PathRadiance *L)
{
#ifdef __EMISSION__
if(!kernel_data.integrator.use_direct_light)
return;
/* sample illumination from lights to find path contribution */
float light_t = path_state_rng_1D(kg, rng, state, PRNG_LIGHT);
float light_u, light_v;
path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v);
Ray light_ray;
BsdfEval L_light;
LightSample ls;
bool is_lamp;
/* connect to light from given point where shader has been evaluated */
#ifdef __OBJECT_MOTION__
light_ray.time = sd->time;
#endif
light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
if(ls.pdf == 0.0f)
return;
if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_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
}
ccl_device bool kernel_path_volume_bounce(KernelGlobals *kg, RNG *rng,
ShaderData *sd, float3 *throughput, PathState *state, PathRadiance *L, Ray *ray)
{
/* sample phase function */
float phase_pdf;
BsdfEval phase_eval;
float3 phase_omega_in;
differential3 phase_domega_in;
float phase_u, phase_v;
path_state_rng_2D(kg, rng, state, PRNG_PHASE_U, &phase_u, &phase_v);
int label;
label = shader_volume_phase_sample(kg, sd, phase_u, phase_v, &phase_eval,
&phase_omega_in, &phase_domega_in, &phase_pdf);
if(phase_pdf == 0.0f || bsdf_eval_is_zero(&phase_eval))
return false;
/* modify throughput */
path_radiance_bsdf_bounce(L, throughput, &phase_eval, phase_pdf, state->bounce, label);
/* set labels */
state->ray_pdf = phase_pdf;
#ifdef __LAMP_MIS__
state->ray_t = 0.0f;
#endif
state->min_ray_pdf = fminf(phase_pdf, state->min_ray_pdf);
/* update path state */
path_state_next(kg, state, label);
/* setup ray */
ray->P = sd->P;
ray->D = phase_omega_in;
ray->t = FLT_MAX;
#ifdef __RAY_DIFFERENTIALS__
ray->dP = sd->dP;
ray->dD = phase_domega_in;
#endif
return true;
}
ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG *rng,
ShaderData *sd, float3 throughput, PathState *state, PathRadiance *L,
float num_samples_adjust, bool sample_all_lights, Ray *ray, const VolumeSegment *segment)
{
#ifdef __EMISSION__
if(!kernel_data.integrator.use_direct_light)
return;
Ray light_ray;
BsdfEval L_light;
bool is_lamp;
#ifdef __OBJECT_MOTION__
light_ray.time = sd->time;
#endif
if(sample_all_lights) {
/* 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++) {
/* sample random position on given light */
float light_u, light_v;
path_branched_rng_2D(kg, &lamp_rng, state, j, num_samples, PRNG_LIGHT_U, &light_u, &light_v);
LightSample ls;
lamp_light_sample(kg, i, light_u, light_v, ray->P, &ls);
float3 tp = throughput;
/* sample position on volume segment */
float rphase = path_branched_rng_1D_for_decision(kg, rng, state, j, num_samples, PRNG_PHASE);
float rscatter = path_branched_rng_1D_for_decision(kg, rng, state, j, num_samples, PRNG_SCATTER_DISTANCE);
VolumeIntegrateResult result = kernel_volume_decoupled_scatter(kg,
state, ray, sd, &tp, rphase, rscatter, segment, (ls.t != FLT_MAX)? &ls.P: NULL, false);
(void)result;
kernel_assert(result == VOLUME_PATH_SCATTERED);
/* todo: split up light_sample so we don't have to call it again with new position */
lamp_light_sample(kg, i, light_u, light_v, sd->P, &ls);
if(ls.pdf == 0.0f)
continue;
if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(L, tp*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++) {
/* sample random position on random triangle */
float light_t = path_branched_rng_1D_for_decision(kg, rng, state, j, num_samples, PRNG_LIGHT);
float light_u, light_v;
path_branched_rng_2D(kg, rng, state, j, num_samples, PRNG_LIGHT_U, &light_u, &light_v);
/* only sample triangle lights */
if(kernel_data.integrator.num_all_lights)
light_t = 0.5f*light_t;
LightSample ls;
light_sample(kg, light_t, light_u, light_v, sd->time, ray->P, &ls);
float3 tp = throughput;
/* sample position on volume segment */
float rphase = path_branched_rng_1D_for_decision(kg, rng, state, j, num_samples, PRNG_PHASE);
float rscatter = path_branched_rng_1D_for_decision(kg, rng, state, j, num_samples, PRNG_SCATTER_DISTANCE);
VolumeIntegrateResult result = kernel_volume_decoupled_scatter(kg,
state, ray, sd, &tp, rphase, rscatter, segment, (ls.t != FLT_MAX)? &ls.P: NULL, false);
(void)result;
kernel_assert(result == VOLUME_PATH_SCATTERED);
/* todo: split up light_sample so we don't have to call it again with new position */
light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
if(ls.pdf == 0.0f)
continue;
if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(L, tp*num_samples_inv, &L_light, shadow, num_samples_inv, state->bounce, is_lamp);
}
}
}
}
}
else {
/* sample random position on random light */
float light_t = path_state_rng_1D(kg, rng, state, PRNG_LIGHT);
float light_u, light_v;
path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v);
LightSample ls;
light_sample(kg, light_t, light_u, light_v, sd->time, ray->P, &ls);
float3 tp = throughput;
/* sample position on volume segment */
float rphase = path_state_rng_1D_for_decision(kg, rng, state, PRNG_PHASE);
float rscatter = path_state_rng_1D_for_decision(kg, rng, state, PRNG_SCATTER_DISTANCE);
VolumeIntegrateResult result = kernel_volume_decoupled_scatter(kg,
state, ray, sd, &tp, rphase, rscatter, segment, (ls.t != FLT_MAX)? &ls.P: NULL, false);
(void)result;
kernel_assert(result == VOLUME_PATH_SCATTERED);
/* todo: split up light_sample so we don't have to call it again with new position */
light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
if(ls.pdf == 0.0f)
return;
/* sample random light */
if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
/* trace shadow ray */
float3 shadow;
if(!shadow_blocked(kg, state, &light_ray, &shadow)) {
/* accumulate */
path_radiance_accum_light(L, tp, &L_light, shadow, 1.0f, state->bounce, is_lamp);
}
}
}
#endif
}
#endif
CCL_NAMESPACE_END