/* * Copyright 2011-2015 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. */ #include "kernel_split.h" /* * Note on kernel_ocl_path_trace_holdout_emission_blurring_pathtermination_ao kernel. * This is the sixth kernel in the ray tracing logic. This is the fifth * of the path iteration kernels. This kernel takes care of the logic to process * "material of type holdout", indirect primitive emission, bsdf blurring, * probabilistic path termination and AO. * * This kernels determines the rays for which a shadow_blocked() function associated with AO should be executed. * Those rays for which a shadow_blocked() function for AO must be executed are marked with flag RAY_SHADOW_RAY_CAST_ao and * enqueued into the queue QUEUE_SHADOW_RAY_CAST_AO_RAYS * * Ray state of rays that are terminated in this kernel are changed to RAY_UPDATE_BUFFER * * The input and output are as follows, * * rng_coop ---------------------------------------------|--- kernel_ocl_path_trace_holdout_emission_blurring_pathtermination_ao ---|--- Queue_index (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS) * throughput_coop --------------------------------------| |--- PathState_coop * PathRadiance_coop ------------------------------------| |--- throughput_coop * Intersection_coop ------------------------------------| |--- L_transparent_coop * PathState_coop ---------------------------------------| |--- per_sample_output_buffers * L_transparent_coop -----------------------------------| |--- PathRadiance_coop * shader_data ------------------------------------------| |--- ShaderData * ray_state --------------------------------------------| |--- ray_state * Queue_data (QUEUE_ACTIVE_AND_REGENERATED_RAYS) -------| |--- Queue_data (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS) * Queue_index (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS) ---| |--- AOAlpha_coop * kg (globals + data) ----------------------------------| |--- AOBSDF_coop * parallel_samples -------------------------------------| |--- AOLightRay_coop * per_sample_output_buffers ----------------------------| | * sw ---------------------------------------------------| | * sh ---------------------------------------------------| | * sx ---------------------------------------------------| | * sy ---------------------------------------------------| | * stride -----------------------------------------------| | * work_array -------------------------------------------| | * queuesize --------------------------------------------| | * start_sample -----------------------------------------| | * * Note on Queues : * This kernel fetches rays from the queue QUEUE_ACTIVE_AND_REGENERATED_RAYS and processes only * the rays of state RAY_ACTIVE. * There are different points in this kernel where a ray may terminate and reach RAY_UPDATE_BUFFER * state. These rays are enqueued into QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS queue. These rays will * still be present in QUEUE_ACTIVE_AND_REGENERATED_RAYS queue, but since their ray-state has been * changed to RAY_UPDATE_BUFFER, there is no problem. * * State of queues when this kernel is called : * At entry, * QUEUE_ACTIVE_AND_REGENERATED_RAYS will be filled with RAY_ACTIVE and RAY_REGENERATED rays * QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS will be filled with RAY_TO_REGENERATE rays. * QUEUE_SHADOW_RAY_CAST_AO_RAYS will be empty. * At exit, * QUEUE_ACTIVE_AND_REGENERATED_RAYS will be filled with RAY_ACTIVE, RAY_REGENERATED and RAY_UPDATE_BUFFER rays * QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS will be filled with RAY_TO_REGENERATE and RAY_UPDATE_BUFFER rays * QUEUE_SHADOW_RAY_CAST_AO_RAYS will be filled with rays marked with flag RAY_SHADOW_RAY_CAST_AO */ __kernel void kernel_ocl_path_trace_holdout_emission_blurring_pathtermination_ao( ccl_global char *globals, ccl_constant KernelData *data, ccl_global char *shader_data, /* Required throughout the kernel except probabilistic path termination and AO */ ccl_global float *per_sample_output_buffers, ccl_global uint *rng_coop, /* Required for "kernel_write_data_passes" and AO */ ccl_global float3 *throughput_coop, /* Required for handling holdout material and AO */ ccl_global float *L_transparent_coop, /* Required for handling holdout material */ PathRadiance *PathRadiance_coop, /* Required for "kernel_write_data_passes" and indirect primitive emission */ ccl_global PathState *PathState_coop, /* Required throughout the kernel and AO */ Intersection *Intersection_coop, /* Required for indirect primitive emission */ ccl_global float3 *AOAlpha_coop, /* Required for AO */ ccl_global float3 *AOBSDF_coop, /* Required for AO */ ccl_global Ray *AOLightRay_coop, /* Required for AO */ int sw, int sh, int sx, int sy, int stride, ccl_global char *ray_state, /* Denotes the state of each ray */ ccl_global unsigned int *work_array, /* Denotes the work that each ray belongs to */ ccl_global int *Queue_data, /* Queue memory */ ccl_global int *Queue_index, /* Tracks the number of elements in each queue */ int queuesize, /* Size (capacity) of each queue */ #ifdef __WORK_STEALING__ unsigned int start_sample, #endif int parallel_samples /* Number of samples to be processed in parallel */ ) { ccl_local unsigned int local_queue_atomics_bg; ccl_local unsigned int local_queue_atomics_ao; if(get_local_id(0) == 0 && get_local_id(1) == 0) { local_queue_atomics_bg = 0; local_queue_atomics_ao = 0; } barrier(CLK_LOCAL_MEM_FENCE); char enqueue_flag = 0; char enqueue_flag_AO_SHADOW_RAY_CAST = 0; int ray_index = get_global_id(1) * get_global_size(0) + get_global_id(0); ray_index = get_ray_index(ray_index, QUEUE_ACTIVE_AND_REGENERATED_RAYS, Queue_data, queuesize, 0); #ifdef __COMPUTE_DEVICE_GPU__ /* If we are executing on a GPU device, we exit all threads that are not required * If we are executing on a CPU device, then we need to keep all threads active * since we have barrier() calls later in the kernel. CPU devices * expect all threads to execute barrier statement. */ if(ray_index == QUEUE_EMPTY_SLOT) return; #endif #ifndef __COMPUTE_DEVICE_GPU__ if(ray_index != QUEUE_EMPTY_SLOT) { #endif /* Load kernel globals structure and ShaderData structure */ KernelGlobals *kg = (KernelGlobals *)globals; ShaderData *sd = (ShaderData *)shader_data; #ifdef __WORK_STEALING__ unsigned int my_work; unsigned int pixel_x; unsigned int pixel_y; #endif unsigned int tile_x; unsigned int tile_y; int my_sample_tile; unsigned int sample; ccl_global RNG *rng = 0x0; ccl_global PathState *state = 0x0; float3 throughput; if(IS_STATE(ray_state, ray_index, RAY_ACTIVE)) { throughput = throughput_coop[ray_index]; state = &PathState_coop[ray_index]; rng = &rng_coop[ray_index]; #ifdef __WORK_STEALING__ my_work = work_array[ray_index]; sample = get_my_sample(my_work, sw, sh, parallel_samples, ray_index) + start_sample; get_pixel_tile_position(&pixel_x, &pixel_y, &tile_x, &tile_y, my_work, sw, sh, sx, sy, parallel_samples, ray_index); my_sample_tile = 0; #else // __WORK_STEALING__ sample = work_array[ray_index]; /* buffer's stride is "stride"; Find x and y using ray_index */ int tile_index = ray_index / parallel_samples; tile_x = tile_index % sw; tile_y = tile_index / sw; my_sample_tile = ray_index - (tile_index * parallel_samples); #endif // __WORK_STEALING__ per_sample_output_buffers += (((tile_x + (tile_y * stride)) * parallel_samples) + my_sample_tile) * kernel_data.film.pass_stride; /* holdout */ #ifdef __HOLDOUT__ if((ccl_fetch(sd, flag) & (SD_HOLDOUT|SD_HOLDOUT_MASK)) && (state->flag & PATH_RAY_CAMERA)) { if(kernel_data.background.transparent) { float3 holdout_weight; if(ccl_fetch(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_coop[ray_index] += average(holdout_weight*throughput); } if(ccl_fetch(sd, flag) & SD_HOLDOUT_MASK) { ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER); enqueue_flag = 1; } } #endif } if(IS_STATE(ray_state, ray_index, RAY_ACTIVE)) { PathRadiance *L = &PathRadiance_coop[ray_index]; /* holdout mask objects do not write data passes */ kernel_write_data_passes(kg, per_sample_output_buffers, L, sd, sample, 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(ccl_fetch(sd, flag) & SD_EMISSION) { /* todo: is isect.t wrong here for transparent surfaces? */ float3 emission = indirect_primitive_emission(kg, sd, Intersection_coop[ray_index].t, state->flag, state->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) { ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER); enqueue_flag = 1; } if(IS_STATE(ray_state, ray_index, RAY_ACTIVE)) { if(probability != 1.0f) { float terminate = path_state_rng_1D_for_decision(kg, rng, state, PRNG_TERMINATE); if(terminate >= probability) { ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER); enqueue_flag = 1; } else { throughput_coop[ray_index] = throughput/probability; } } } } #ifdef __AO__ if(IS_STATE(ray_state, ray_index, RAY_ACTIVE)) { /* ambient occlusion */ if(kernel_data.integrator.use_ambient_occlusion || (ccl_fetch(sd, flag) & SD_AO)) { /* todo: solve correlation */ float bsdf_u, bsdf_v; path_state_rng_2D(kg, rng, state, PRNG_BSDF_U, &bsdf_u, &bsdf_v); float ao_factor = kernel_data.background.ao_factor; float3 ao_N; AOBSDF_coop[ray_index] = shader_bsdf_ao(kg, sd, ao_factor, &ao_N); AOAlpha_coop[ray_index] = shader_bsdf_alpha(kg, sd); float3 ao_D; float ao_pdf; sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf); if(dot(ccl_fetch(sd, Ng), ao_D) > 0.0f && ao_pdf != 0.0f) { Ray _ray; _ray.P = ray_offset(ccl_fetch(sd, P), ccl_fetch(sd, Ng)); _ray.D = ao_D; _ray.t = kernel_data.background.ao_distance; #ifdef __OBJECT_MOTION__ _ray.time = ccl_fetch(sd, time); #endif _ray.dP = ccl_fetch(sd, dP); _ray.dD = differential3_zero(); AOLightRay_coop[ray_index] = _ray; ADD_RAY_FLAG(ray_state, ray_index, RAY_SHADOW_RAY_CAST_AO); enqueue_flag_AO_SHADOW_RAY_CAST = 1; } } } #endif #ifndef __COMPUTE_DEVICE_GPU__ } #endif /* Enqueue RAY_UPDATE_BUFFER rays */ enqueue_ray_index_local(ray_index, QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS, enqueue_flag, queuesize, &local_queue_atomics_bg, Queue_data, Queue_index); #ifdef __AO__ /* Enqueue to-shadow-ray-cast rays */ enqueue_ray_index_local(ray_index, QUEUE_SHADOW_RAY_CAST_AO_RAYS, enqueue_flag_AO_SHADOW_RAY_CAST, queuesize, &local_queue_atomics_ao, Queue_data, Queue_index); #endif }