Commit: d8b42751625c915113b64f5a2d9c72f19f009fee Author: Alaska Date: Thu Dec 9 09:12:24 2021 +0100 Branches: master https://developer.blender.org/rBd8b42751625c915113b64f5a2d9c72f19f009fee
Cycles-X: Add hysteresis to resolution divider algorithm Adds hysteresis to the resolution divider algorithm to avoid having the resolution bounce around when on the boundary of two resolutions. Reviewed By: brecht, leesonw Differential Revision: https://developer.blender.org/D12385 =================================================================== M intern/cycles/integrator/render_scheduler.cpp M intern/cycles/integrator/render_scheduler.h =================================================================== diff --git a/intern/cycles/integrator/render_scheduler.cpp b/intern/cycles/integrator/render_scheduler.cpp index ac82b151f45..4a73955a95f 100644 --- a/intern/cycles/integrator/render_scheduler.cpp +++ b/intern/cycles/integrator/render_scheduler.cpp @@ -1085,14 +1085,8 @@ void RenderScheduler::update_start_resolution_divider() first_render_time_.denoise_time + first_render_time_.display_update_time; - /* Allow some percent of tolerance, so that if the render time is close enough to the higher - * resolution we prefer to use it instead of going way lower resolution and time way below the - * desired one. */ const int resolution_divider_for_update = calculate_resolution_divider_for_time( - desired_update_interval_in_seconds * 1.4, actual_time_per_update); - - /* TODO(sergey): Need to add hysteresis to avoid resolution divider bouncing around when actual - * render time is somewhere on a boundary between two resolutions. */ + desired_update_interval_in_seconds, actual_time_per_update, start_resolution_divider_); /* Never increase resolution to higher than the pixel size (which is possible if the scene is * simple and compute device is fast). */ @@ -1179,12 +1173,14 @@ void RenderScheduler::check_time_limit_reached() * Utility functions. */ -int RenderScheduler::calculate_resolution_divider_for_time(double desired_time, double actual_time) +int RenderScheduler::calculate_resolution_divider_for_time(double desired_time, + double actual_time, + int previous_resolution_divider) { /* TODO(sergey): There should a non-iterative analytical formula here. */ int resolution_divider = 1; - + double pre_division_time = actual_time; /* This algorithm iterates through resolution dividers until a divider is found that achieves * the desired render time. A limit of default_start_resolution_divider_ is put in place as the * maximum resolution divider to avoid an unreadable viewport due to a low resolution. @@ -1192,12 +1188,26 @@ int RenderScheduler::calculate_resolution_divider_for_time(double desired_time, * calculation to better predict the performance impact of changing resolution divisions as * the sample count can also change between resolution divisions. */ while (actual_time > desired_time && resolution_divider < default_start_resolution_divider_) { + pre_division_time = actual_time; int pre_resolution_division_samples = get_num_samples_during_navigation(resolution_divider); resolution_divider = resolution_divider * 2; int post_resolution_division_samples = get_num_samples_during_navigation(resolution_divider); actual_time /= 4.0 * pre_resolution_division_samples / post_resolution_division_samples; } + /* Hysteresis to avoid resolution divider bouncing around when actual render time is somewhere + * on a boundary between two resolutions. This system allows some percentage of tolerance so + * that the viewport tends towards remaining at higher resolutions rather than dropping to a + * lower resolution if performance is close to, but not quite reaching the target frame rate. + * This system also tends to not increase the viewport resolution unless the hardware can + * exceed the performance target by a certain percentage. This is to help ensure the viewport + * remains responsive after increasing the resolution. */ + if (resolution_divider > previous_resolution_divider && pre_division_time < desired_time * 1.5) { + return resolution_divider / 2; + } + if (resolution_divider < previous_resolution_divider && pre_division_time > desired_time / 1.3) { + return resolution_divider * 2; + } return resolution_divider; } diff --git a/intern/cycles/integrator/render_scheduler.h b/intern/cycles/integrator/render_scheduler.h index 28f563c46e3..705bb3b46ba 100644 --- a/intern/cycles/integrator/render_scheduler.h +++ b/intern/cycles/integrator/render_scheduler.h @@ -462,7 +462,9 @@ class RenderScheduler { * desired one. This call assumes linear dependency of render time from number of pixels * (quadratic dependency from the resolution divider): resolution divider of 2 brings render time * down by a factor of 4. */ - int calculate_resolution_divider_for_time(double desired_time, double actual_time); + int calculate_resolution_divider_for_time(double desired_time, + double actual_time, + int previous_resolution_divider); }; int calculate_resolution_divider_for_resolution(int width, int height, int resolution); _______________________________________________ Bf-blender-cvs mailing list Bf-blender-cvs@blender.org List details, subscription details or unsubscribe: https://lists.blender.org/mailman/listinfo/bf-blender-cvs
