Commit: cdb47b9dfc2d30345748d6736702e06f7e5d0369 Author: Thomas Dinges Date: Thu Mar 12 11:58:43 2015 +0100 Branches: master https://developer.blender.org/rBcdb47b9dfc2d30345748d6736702e06f7e5d0369
Cycles: Make Background MIS building threaded Use multiple threads for building the MIS table, if the resolution is higher than 512. Also replace division by cdf_total, with a inverse multiplication by cdf_total_inv. This gives further speedup. On my Macbook (8 CPU threads) this improves the time to build the table: Resolution 4096: From 0.16s to 0.03s Resolution 8096: From 0.61s to 0.11s This especially helps to reduce the scene update time, when tweaking world shader while viewport rendering is running. Patch by Sergey and myself. Differential Revision: https://developer.blender.org/D1159 =================================================================== M intern/cycles/render/light.cpp =================================================================== diff --git a/intern/cycles/render/light.cpp b/intern/cycles/render/light.cpp index 284012e..56bec40 100644 --- a/intern/cycles/render/light.cpp +++ b/intern/cycles/render/light.cpp @@ -26,6 +26,7 @@ #include "util_foreach.h" #include "util_progress.h" +#include "util_logging.h" CCL_NAMESPACE_BEGIN @@ -377,6 +378,45 @@ void LightManager::device_update_distribution(Device *device, DeviceScene *dscen } } +static void background_cdf(int start, + int end, + int res, + int cdf_count, + const vector<float3> *pixels, + float2 *cond_cdf) +{ + /* Conditional CDFs (rows, U direction). */ + for(int i = start; i < end; i++) { + float sin_theta = sinf(M_PI_F * (i + 0.5f) / res); + float3 env_color = (*pixels)[i * res]; + float ave_luminamce = average(env_color); + + cond_cdf[i * cdf_count].x = ave_luminamce * sin_theta; + cond_cdf[i * cdf_count].y = 0.0f; + + for(int j = 1; j < res; j++) { + env_color = (*pixels)[i * res + j]; + ave_luminamce = average(env_color); + + cond_cdf[i * cdf_count + j].x = ave_luminamce * sin_theta; + cond_cdf[i * cdf_count + j].y = cond_cdf[i * cdf_count + j - 1].y + cond_cdf[i * cdf_count + j - 1].x / res; + } + + float cdf_total = cond_cdf[i * cdf_count + res - 1].y + cond_cdf[i * cdf_count + res - 1].x / res; + float cdf_total_inv = 1.0f / cdf_total; + + /* stuff the total into the brightness value for the last entry, because + * we are going to normalize the CDFs to 0.0 to 1.0 afterwards */ + cond_cdf[i * cdf_count + res].x = cdf_total; + + if(cdf_total > 0.0f) + for(int j = 1; j < res; j++) + cond_cdf[i * cdf_count + j].y *= cdf_total_inv; + + cond_cdf[i * cdf_count + res].y = 1.0f; + } +} + void LightManager::device_update_background(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress) { KernelIntegrator *kintegrator = &dscene->data.integrator; @@ -417,34 +457,28 @@ void LightManager::device_update_background(Device *device, DeviceScene *dscene, float2 *marg_cdf = dscene->light_background_marginal_cdf.resize(cdf_count); float2 *cond_cdf = dscene->light_background_conditional_cdf.resize(cdf_count * cdf_count); - /* conditional CDFs (rows, U direction) */ - for(int i = 0; i < res; i++) { - float sin_theta = sinf(M_PI_F * (i + 0.5f) / res); - float3 env_color = pixels[i * res]; - float ave_luminamce = average(env_color); - - cond_cdf[i * cdf_count].x = ave_luminamce * sin_theta; - cond_cdf[i * cdf_count].y = 0.0f; - - for(int j = 1; j < res; j++) { - env_color = pixels[i * res + j]; - ave_luminamce = average(env_color); - - cond_cdf[i * cdf_count + j].x = ave_luminamce * sin_theta; - cond_cdf[i * cdf_count + j].y = cond_cdf[i * cdf_count + j - 1].y + cond_cdf[i * cdf_count + j - 1].x / res; + double time_start = time_dt(); + if(res < 512) { + /* Small enough resolution, faster to do single-threaded. */ + background_cdf(0, res, res, cdf_count, &pixels, cond_cdf); + } + else { + /* Threaded evaluation for large resolution. */ + const int num_blocks = TaskScheduler::num_threads(); + const int chunk_size = res / num_blocks; + TaskPool pool; + for(int i = 0; i < num_blocks; ++i) { + const int current_chunk_size = + (i != num_blocks - 1) ? chunk_size + : (res - i * chunk_size); + pool.push(function_bind(&background_cdf, + i, i + current_chunk_size, + res, + cdf_count, + &pixels, + cond_cdf)); } - - float cdf_total = cond_cdf[i * cdf_count + res - 1].y + cond_cdf[i * cdf_count + res - 1].x / res; - - /* stuff the total into the brightness value for the last entry, because - * we are going to normalize the CDFs to 0.0 to 1.0 afterwards */ - cond_cdf[i * cdf_count + res].x = cdf_total; - - if(cdf_total > 0.0f) - for(int j = 1; j < res; j++) - cond_cdf[i * cdf_count + j].y /= cdf_total; - - cond_cdf[i * cdf_count + res].y = 1.0f; + pool.wait_work(); } /* marginal CDFs (column, V direction, sum of rows) */ @@ -465,6 +499,8 @@ void LightManager::device_update_background(Device *device, DeviceScene *dscene, marg_cdf[res].y = 1.0f; + VLOG(2) << "Background MIS build time " << time_dt() - time_start << "\n"; + /* update device */ device->tex_alloc("__light_background_marginal_cdf", dscene->light_background_marginal_cdf); device->tex_alloc("__light_background_conditional_cdf", dscene->light_background_conditional_cdf); _______________________________________________ Bf-blender-cvs mailing list Bf-blender-cvs@blender.org http://lists.blender.org/mailman/listinfo/bf-blender-cvs
