/* * 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 "kernel/osl/osl_shader.h" #endif #include "kernel/kernel_random.h" #include "kernel/kernel_projection.h" #include "kernel/kernel_montecarlo.h" #include "kernel/kernel_differential.h" #include "kernel/kernel_camera.h" #include "kernel/geom/geom.h" #include "kernel/bvh/bvh.h" #include "kernel/kernel_accumulate.h" #include "kernel/kernel_shader.h" #include "kernel/kernel_light.h" #include "kernel/kernel_passes.h" #if defined(__VOLUME__) || defined(__SUBSURFACE__) # include "kernel/kernel_volume.h" #endif #ifdef __SUBSURFACE__ # include "kernel/kernel_subsurface.h" #endif #include "kernel/kernel_path_state.h" #include "kernel/kernel_shadow.h" #include "kernel/kernel_emission.h" #include "kernel/kernel_path_common.h" #include "kernel/kernel_path_surface.h" #include "kernel/kernel_path_volume.h" #include "kernel/kernel_path_subsurface.h" CCL_NAMESPACE_BEGIN ccl_device_forceinline bool kernel_path_scene_intersect( KernelGlobals *kg, ccl_addr_space PathState *state, Ray *ray, Intersection *isect, PathRadiance *L) { PROFILING_INIT(kg, PROFILING_SCENE_INTERSECT); uint visibility = path_state_ray_visibility(kg, state); if(path_state_ao_bounce(kg, state)) { visibility = PATH_RAY_SHADOW; ray->t = kernel_data.background.ao_distance; } #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_state_init_addrspace(state, 0x51633e2d); } bool hit = scene_intersect(kg, *ray, visibility, isect, &lcg_state, difl, extmax); #else bool hit = scene_intersect(kg, *ray, visibility, isect, NULL, 0.0f, 0.0f); #endif /* __HAIR__ */ #ifdef __KERNEL_DEBUG__ if(state->flag & PATH_RAY_CAMERA) { L->debug_data.num_bvh_traversed_nodes += isect->num_traversed_nodes; L->debug_data.num_bvh_traversed_instances += isect->num_traversed_instances; L->debug_data.num_bvh_intersections += isect->num_intersections; } L->debug_data.num_ray_bounces++; #endif /* __KERNEL_DEBUG__ */ return hit; } ccl_device_forceinline void kernel_path_lamp_emission( KernelGlobals *kg, ccl_addr_space PathState *state, Ray *ray, float3 throughput, ccl_addr_space Intersection *isect, ShaderData *emission_sd, PathRadiance *L) { PROFILING_INIT(kg, PROFILING_INDIRECT_EMISSION); #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 - state->ray_t*ray->D; state->ray_t += isect->t; light_ray.D = ray->D; light_ray.t = state->ray_t; light_ray.time = ray->time; light_ray.dD = ray->dD; light_ray.dP = ray->dP; /* intersect with lamp */ float3 emission; if(indirect_lamp_emission(kg, emission_sd, state, &light_ray, &emission)) path_radiance_accum_emission(L, state, throughput, emission); } #endif /* __LAMP_MIS__ */ } ccl_device_forceinline void kernel_path_background( KernelGlobals *kg, ccl_addr_space PathState *state, ccl_addr_space Ray *ray, float3 throughput, ShaderData *sd, PathRadiance *L) { /* eval background shader if nothing hit */ if(kernel_data.background.transparent && (state->flag & PATH_RAY_TRANSPARENT_BACKGROUND)) { L->transparent += average(throughput); #ifdef __PASSES__ if(!(kernel_data.film.light_pass_flag & PASSMASK(BACKGROUND))) #endif /* __PASSES__ */ return; } /* When using the ao bounces approximation, adjust background * shader intensity with ao factor. */ if(path_state_ao_bounce(kg, state)) { throughput *= kernel_data.background.ao_bounces_factor; } #ifdef __BACKGROUND__ /* sample background shader */ float3 L_background = indirect_background(kg, sd, state, ray); path_radiance_accum_background(L, state, throughput, L_background); #endif /* __BACKGROUND__ */ } #ifndef __SPLIT_KERNEL__ #ifdef __VOLUME__ ccl_device_forceinline VolumeIntegrateResult kernel_path_volume( KernelGlobals *kg, ShaderData *sd, PathState *state, Ray *ray, float3 *throughput, ccl_addr_space Intersection *isect, bool hit, ShaderData *emission_sd, PathRadiance *L) { PROFILING_INIT(kg, PROFILING_VOLUME); /* Sanitize volume stack. */ if(!hit) { kernel_volume_clean_stack(kg, state->volume_stack); } if(state->volume_stack[0].shader == SHADER_NONE) { return VOLUME_PATH_ATTENUATED; } /* volume attenuation, emission, scatter */ Ray volume_ray = *ray; volume_ray.t = (hit)? isect->t: FLT_MAX; bool heterogeneous = volume_stack_is_heterogeneous(kg, state->volume_stack); # ifdef __VOLUME_DECOUPLED__ int sampling_method = volume_stack_sampling_method(kg, state->volume_stack); bool direct = (state->flag & PATH_RAY_CAMERA) != 0; bool decoupled = kernel_volume_use_decoupled(kg, heterogeneous, direct, sampling_method); if(decoupled) { /* cache steps along volume for repeated sampling */ VolumeSegment volume_segment; shader_setup_from_volume(kg, sd, &volume_ray); kernel_volume_decoupled_record(kg, state, &volume_ray, sd, &volume_segment, heterogeneous); volume_segment.sampling_method = sampling_method; /* emission */ if(volume_segment.closure_flag & SD_EMISSION) path_radiance_accum_emission(L, state, *throughput, volume_segment.accum_emission); /* scattering */ VolumeIntegrateResult result = VOLUME_PATH_ATTENUATED; if(volume_segment.closure_flag & SD_SCATTER) { int all = kernel_data.integrator.sample_all_lights_indirect; /* direct light sampling */ kernel_branched_path_volume_connect_light(kg, sd, emission_sd, *throughput, state, L, all, &volume_ray, &volume_segment); /* indirect sample. if we use distance sampling and take just * one sample for direct and indirect light, we could share * this computation, but makes code a bit complex */ float rphase = path_state_rng_1D(kg, state, PRNG_PHASE_CHANNEL); float rscatter = path_state_rng_1D(kg, state, PRNG_SCATTER_DISTANCE); result = kernel_volume_decoupled_scatter(kg, state, &volume_ray, sd, throughput, rphase, rscatter, &volume_segment, NULL, true); } /* free cached steps */ kernel_volume_decoupled_free(kg, &volume_segment); if(result == VOLUME_PATH_SCATTERED) { if(kernel_path_volume_bounce(kg, sd, throughput, state, &L->state, ray)) return VOLUME_PATH_SCATTERED; else return VOLUME_PATH_MISSED; } else { *throughput *= volume_segment.accum_transmittance; } } else # endif /* __VOLUME_DECOUPLED__ */ { /* integrate along volume segment with distance sampling */ VolumeIntegrateResult result = kernel_volume_integrate( kg, state, sd, &volume_ray, L, throughput, heterogeneous); # ifdef __VOLUME_SCATTER__ if(result == VOLUME_PATH_SCATTERED) { /* direct lighting */ kernel_path_volume_connect_light(kg, sd, emission_sd, *throughput, state, L); /* indirect light bounce */ if(kernel_path_volume_bounce(kg, sd, throughput, state, &L->state, ray)) return VOLUME_PATH_SCATTERED; else return VOLUME_PATH_MISSED; } # endif /* __VOLUME_SCATTER__ */ } return VOLUME_PATH_ATTENUATED; } #endif /* __VOLUME__ */ #endif /* __SPLIT_KERNEL__ */ ccl_device_forceinline bool kernel_path_shader_apply( KernelGlobals *kg, ShaderData *sd, ccl_addr_space PathState *state, ccl_addr_space Ray *ray, float3 throughput, ShaderData *emission_sd, PathRadiance *L, ccl_global float *buffer) { PROFILING_INIT(kg, PROFILING_SHADER_APPLY); #ifdef __SHADOW_TRICKS__ if((sd->object_flag & SD_OBJECT_SHADOW_CATCHER)) { if(state->flag & PATH_RAY_TRANSPARENT_BACKGROUND) { state->flag |= (PATH_RAY_SHADOW_CATCHER | PATH_RAY_STORE_SHADOW_INFO); float3 bg = make_float3(0.0f, 0.0f, 0.0f); if(!kernel_data.background.transparent) { bg = indirect_background(kg, emission_sd, state, ray); } path_radiance_accum_shadowcatcher(L, throughput, bg); } } else if(state->flag & PATH_RAY_SHADOW_CATCHER) { /* Only update transparency after shadow catcher bounce. */ L->shadow_transparency *= average(shader_bsdf_transparency(kg, sd)); } #endif /* __SHADOW_TRICKS__ */ /* holdout */ #ifdef __HOLDOUT__ if(((sd->flag & SD_HOLDOUT) || (sd->object_flag & SD_OBJECT_HOLDOUT_MASK)) && (state->flag & PATH_RAY_TRANSPARENT_BACKGROUND)) { if(kernel_data.background.transparent) { float3 holdout_weight; if(sd->object_flag & SD_OBJECT_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->object_flag & SD_OBJECT_HOLDOUT_MASK) { return false; } } #endif /* __HOLDOUT__ */ /* holdout mask objects do not write data passes */ kernel_write_data_passes(kg, buffer, L, sd, state, 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*state->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, sd->ray_length, state->flag, state->ray_pdf); path_radiance_accum_emission(L, state, throughput, emission); } #endif /* __EMISSION__ */ return true; } ccl_device_noinline void kernel_path_ao(KernelGlobals *kg, ShaderData *sd, ShaderData *emission_sd, PathRadiance *L, ccl_addr_space PathState *state, float3 throughput, float3 ao_alpha) { PROFILING_INIT(kg, PROFILING_AO); /* todo: solve correlation */ float bsdf_u, bsdf_v; path_state_rng_2D(kg, state, 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; light_ray.time = sd->time; light_ray.dP = sd->dP; light_ray.dD = differential3_zero(); if(!shadow_blocked(kg, sd, emission_sd, state, &light_ray, &ao_shadow)) { path_radiance_accum_ao(L, state, throughput, ao_alpha, ao_bsdf, ao_shadow); } else { path_radiance_accum_total_ao(L, state, throughput, ao_bsdf); } } } #ifndef __SPLIT_KERNEL__ #if defined(__BRANCHED_PATH__) || defined(__BAKING__) ccl_device void kernel_path_indirect(KernelGlobals *kg, ShaderData *sd, ShaderData *emission_sd, Ray *ray, float3 throughput, PathState *state, PathRadiance *L) { #ifdef __SUBSURFACE__ SubsurfaceIndirectRays ss_indirect; kernel_path_subsurface_init_indirect(&ss_indirect); for(;;) { #endif /* __SUBSURFACE__ */ /* path iteration */ for(;;) { /* Find intersection with objects in scene. */ Intersection isect; bool hit = kernel_path_scene_intersect(kg, state, ray, &isect, L); /* Find intersection with lamps and compute emission for MIS. */ kernel_path_lamp_emission(kg, state, ray, throughput, &isect, sd, L); #ifdef __VOLUME__ /* Volume integration. */ VolumeIntegrateResult result = kernel_path_volume(kg, sd, state, ray, &throughput, &isect, hit, emission_sd, L); if(result == VOLUME_PATH_SCATTERED) { continue; } else if(result == VOLUME_PATH_MISSED) { break; } #endif /* __VOLUME__*/ /* Shade background. */ if(!hit) { kernel_path_background(kg, state, ray, throughput, sd, L); break; } else if(path_state_ao_bounce(kg, state)) { break; } /* Setup shader data. */ shader_setup_from_ray(kg, sd, &isect, ray); /* Skip most work for volume bounding surface. */ #ifdef __VOLUME__ if(!(sd->flag & SD_HAS_ONLY_VOLUME)) { #endif /* Evaluate shader. */ shader_eval_surface(kg, sd, state, state->flag); shader_prepare_closures(sd, state); /* Apply shadow catcher, holdout, emission. */ if(!kernel_path_shader_apply(kg, sd, state, ray, throughput, emission_sd, L, NULL)) { break; } /* 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_continuation_probability(kg, state, throughput); if(probability == 0.0f) { break; } else if(probability != 1.0f) { float terminate = path_state_rng_1D(kg, state, PRNG_TERMINATE); if(terminate >= probability) break; throughput /= probability; } kernel_update_denoising_features(kg, sd, state, L); #ifdef __AO__ /* ambient occlusion */ if(kernel_data.integrator.use_ambient_occlusion) { kernel_path_ao(kg, sd, emission_sd, L, state, throughput, make_float3(0.0f, 0.0f, 0.0f)); } #endif /* __AO__ */ #ifdef __SUBSURFACE__ /* bssrdf scatter to a different location on the same object, replacing * the closures with a diffuse BSDF */ if(sd->flag & SD_BSSRDF) { if(kernel_path_subsurface_scatter(kg, sd, emission_sd, L, state, ray, &throughput, &ss_indirect)) { break; } } #endif /* __SUBSURFACE__ */ #if defined(__EMISSION__) if(kernel_data.integrator.use_direct_light) { int all = (kernel_data.integrator.sample_all_lights_indirect) || (state->flag & PATH_RAY_SHADOW_CATCHER); kernel_branched_path_surface_connect_light(kg, sd, emission_sd, state, throughput, 1.0f, L, all); } #endif /* defined(__EMISSION__) */ #ifdef __VOLUME__ } #endif if(!kernel_path_surface_bounce(kg, sd, &throughput, state, &L->state, ray)) break; } #ifdef __SUBSURFACE__ /* Trace indirect subsurface rays by restarting the loop. this uses less * stack memory than invoking kernel_path_indirect. */ if(ss_indirect.num_rays) { kernel_path_subsurface_setup_indirect(kg, &ss_indirect, state, ray, L, &throughput); } else { break; } } #endif /* __SUBSURFACE__ */ } #endif /* defined(__BRANCHED_PATH__) || defined(__BAKING__) */ ccl_device_forceinline void kernel_path_integrate( KernelGlobals *kg, PathState *state, float3 throughput, Ray *ray, PathRadiance *L, ccl_global float *buffer, ShaderData *emission_sd) { PROFILING_INIT(kg, PROFILING_PATH_INTEGRATE); /* Shader data memory used for both volumes and surfaces, saves stack space. */ ShaderData sd; #ifdef __SUBSURFACE__ SubsurfaceIndirectRays ss_indirect; kernel_path_subsurface_init_indirect(&ss_indirect); for(;;) { #endif /* __SUBSURFACE__ */ /* path iteration */ for(;;) { /* Find intersection with objects in scene. */ Intersection isect; bool hit = kernel_path_scene_intersect(kg, state, ray, &isect, L); /* Find intersection with lamps and compute emission for MIS. */ kernel_path_lamp_emission(kg, state, ray, throughput, &isect, &sd, L); #ifdef __VOLUME__ /* Volume integration. */ VolumeIntegrateResult result = kernel_path_volume(kg, &sd, state, ray, &throughput, &isect, hit, emission_sd, L); if(result == VOLUME_PATH_SCATTERED) { continue; } else if(result == VOLUME_PATH_MISSED) { break; } #endif /* __VOLUME__*/ /* Shade background. */ if(!hit) { kernel_path_background(kg, state, ray, throughput, &sd, L); break; } else if(path_state_ao_bounce(kg, state)) { break; } /* Setup shader data. */ shader_setup_from_ray(kg, &sd, &isect, ray); /* Skip most work for volume bounding surface. */ #ifdef __VOLUME__ if(!(sd.flag & SD_HAS_ONLY_VOLUME)) { #endif /* Evaluate shader. */ shader_eval_surface(kg, &sd, state, state->flag); shader_prepare_closures(&sd, state); /* Apply shadow catcher, holdout, emission. */ if(!kernel_path_shader_apply(kg, &sd, state, ray, throughput, emission_sd, L, buffer)) { break; } /* 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_continuation_probability(kg, state, throughput); if(probability == 0.0f) { break; } else if(probability != 1.0f) { float terminate = path_state_rng_1D(kg, state, PRNG_TERMINATE); if(terminate >= probability) break; throughput /= probability; } kernel_update_denoising_features(kg, &sd, state, L); #ifdef __AO__ /* ambient occlusion */ if(kernel_data.integrator.use_ambient_occlusion) { kernel_path_ao(kg, &sd, emission_sd, L, state, throughput, shader_bsdf_alpha(kg, &sd)); } #endif /* __AO__ */ #ifdef __SUBSURFACE__ /* bssrdf scatter to a different location on the same object, replacing * the closures with a diffuse BSDF */ if(sd.flag & SD_BSSRDF) { if(kernel_path_subsurface_scatter(kg, &sd, emission_sd, L, state, ray, &throughput, &ss_indirect)) { break; } } #endif /* __SUBSURFACE__ */ /* direct lighting */ kernel_path_surface_connect_light(kg, &sd, emission_sd, throughput, state, L); #ifdef __VOLUME__ } #endif /* compute direct lighting and next bounce */ if(!kernel_path_surface_bounce(kg, &sd, &throughput, state, &L->state, ray)) break; } #ifdef __SUBSURFACE__ /* Trace indirect subsurface rays by restarting the loop. this uses less * stack memory than invoking kernel_path_indirect. */ if(ss_indirect.num_rays) { kernel_path_subsurface_setup_indirect(kg, &ss_indirect, state, ray, L, &throughput); } else { break; } } #endif /* __SUBSURFACE__ */ } ccl_device void kernel_path_trace(KernelGlobals *kg, ccl_global float *buffer, int sample, int x, int y, int offset, int stride) { PROFILING_INIT(kg, PROFILING_RAY_SETUP); /* buffer offset */ int index = offset + x + y*stride; int pass_stride = kernel_data.film.pass_stride; buffer += index*pass_stride; /* Initialize random numbers and sample ray. */ uint rng_hash; Ray ray; kernel_path_trace_setup(kg, sample, x, y, &rng_hash, &ray); if(ray.t == 0.0f) { return; } /* Initialize state. */ float3 throughput = make_float3(1.0f, 1.0f, 1.0f); PathRadiance L; path_radiance_init(&L, kernel_data.film.use_light_pass); ShaderDataTinyStorage emission_sd_storage; ShaderData *emission_sd = AS_SHADER_DATA(&emission_sd_storage); PathState state; path_state_init(kg, emission_sd, &state, rng_hash, sample, &ray); /* Integrate. */ kernel_path_integrate(kg, &state, throughput, &ray, &L, buffer, emission_sd); kernel_write_result(kg, buffer, sample, &L); } #endif /* __SPLIT_KERNEL__ */ CCL_NAMESPACE_END