diff options
Diffstat (limited to 'intern/cycles/kernel/kernel_path_subsurface.h')
| -rw-r--r-- | intern/cycles/kernel/kernel_path_subsurface.h | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/intern/cycles/kernel/kernel_path_subsurface.h b/intern/cycles/kernel/kernel_path_subsurface.h new file mode 100644 index 00000000000..10b568ac3dd --- /dev/null +++ b/intern/cycles/kernel/kernel_path_subsurface.h @@ -0,0 +1,187 @@ +/* + * Copyright 2017 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 __SUBSURFACE__ +# ifndef __KERNEL_CUDA__ +ccl_device +# else +ccl_device_inline +# endif +bool kernel_path_subsurface_scatter( + KernelGlobals *kg, + ShaderData *sd, + ShaderData *emission_sd, + PathRadiance *L, + ccl_addr_space PathState *state, + RNG *rng, + ccl_addr_space Ray *ray, + ccl_addr_space float3 *throughput, + ccl_addr_space SubsurfaceIndirectRays *ss_indirect) +{ + 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) { + /* We should never have two consecutive BSSRDF bounces, + * the second one should be converted to a diffuse BSDF to + * avoid this. + */ + kernel_assert(!ss_indirect->tracing); + + uint lcg_state = lcg_state_init(rng, state->rng_offset, state->sample, 0x68bc21eb); + + SubsurfaceIntersection ss_isect; + float bssrdf_u, bssrdf_v; + path_state_rng_2D(kg, rng, state, PRNG_BSDF_U, &bssrdf_u, &bssrdf_v); + int num_hits = subsurface_scatter_multi_intersect(kg, + &ss_isect, + sd, + sc, + &lcg_state, + bssrdf_u, bssrdf_v, + false); +# ifdef __VOLUME__ + ss_indirect->need_update_volume_stack = + kernel_data.integrator.use_volumes && + sd->object_flag & SD_OBJECT_INTERSECTS_VOLUME; +# endif /* __VOLUME__ */ + + /* compute lighting with the BSDF closure */ + for(int hit = 0; hit < num_hits; hit++) { + /* NOTE: We reuse the existing ShaderData, we assume the path + * integration loop stops when this function returns true. + */ + subsurface_scatter_multi_setup(kg, + &ss_isect, + hit, + sd, + state, + state->flag, + sc, + false); + + ccl_addr_space PathState *hit_state = &ss_indirect->state[ss_indirect->num_rays]; + ccl_addr_space Ray *hit_ray = &ss_indirect->rays[ss_indirect->num_rays]; + ccl_addr_space float3 *hit_tp = &ss_indirect->throughputs[ss_indirect->num_rays]; + PathRadiance *hit_L = &ss_indirect->L[ss_indirect->num_rays]; + + *hit_state = *state; + *hit_ray = *ray; + *hit_tp = *throughput; + + hit_state->rng_offset += PRNG_BOUNCE_NUM; + + path_radiance_init(hit_L, kernel_data.film.use_light_pass); + hit_L->direct_throughput = L->direct_throughput; + path_radiance_copy_indirect(hit_L, L); + + kernel_path_surface_connect_light(kg, rng, sd, emission_sd, *hit_tp, state, hit_L); + + if(kernel_path_surface_bounce(kg, + rng, + sd, + hit_tp, + hit_state, + hit_L, + hit_ray)) + { +# ifdef __LAMP_MIS__ + hit_state->ray_t = 0.0f; +# endif /* __LAMP_MIS__ */ + +# ifdef __VOLUME__ + if(ss_indirect->need_update_volume_stack) { + Ray volume_ray = *ray; + /* Setup ray from previous surface point to the new one. */ + volume_ray.D = normalize_len(hit_ray->P - volume_ray.P, + &volume_ray.t); + + kernel_volume_stack_update_for_subsurface( + kg, + emission_sd, + &volume_ray, + hit_state->volume_stack); + } +# endif /* __VOLUME__ */ + path_radiance_reset_indirect(L); + ss_indirect->num_rays++; + } + else { + path_radiance_accum_sample(L, hit_L, 1); + } + } + return true; + } + return false; +} + +ccl_device_inline void kernel_path_subsurface_init_indirect( + ccl_addr_space SubsurfaceIndirectRays *ss_indirect) +{ + ss_indirect->tracing = false; + ss_indirect->num_rays = 0; +} + +ccl_device void kernel_path_subsurface_accum_indirect( + ccl_addr_space SubsurfaceIndirectRays *ss_indirect, + PathRadiance *L) +{ + if(ss_indirect->tracing) { + path_radiance_sum_indirect(L); + path_radiance_accum_sample(&ss_indirect->direct_L, L, 1); + if(ss_indirect->num_rays == 0) { + *L = ss_indirect->direct_L; + } + } +} + +ccl_device void kernel_path_subsurface_setup_indirect( + KernelGlobals *kg, + ccl_addr_space SubsurfaceIndirectRays *ss_indirect, + ccl_addr_space PathState *state, + ccl_addr_space Ray *ray, + PathRadiance *L, + ccl_addr_space float3 *throughput) +{ + if(!ss_indirect->tracing) { + ss_indirect->direct_L = *L; + } + ss_indirect->tracing = true; + + /* Setup state, ray and throughput for indirect SSS rays. */ + ss_indirect->num_rays--; + + ccl_addr_space Ray *indirect_ray = &ss_indirect->rays[ss_indirect->num_rays]; + PathRadiance *indirect_L = &ss_indirect->L[ss_indirect->num_rays]; + + *state = ss_indirect->state[ss_indirect->num_rays]; + *ray = *indirect_ray; + *L = *indirect_L; + *throughput = ss_indirect->throughputs[ss_indirect->num_rays]; + + state->rng_offset += ss_indirect->num_rays * PRNG_BOUNCE_NUM; +} + +#endif /* __SUBSURFACE__ */ + +CCL_NAMESPACE_END + |