From 2229179faa44e2c685b4eabd0c51d4c7d5c1f193 Mon Sep 17 00:00:00 2001 From: Brecht Van Lommel Date: Thu, 16 Dec 2021 18:26:22 +0100 Subject: Revert "Cycles-X: Add hysteresis to resolution divider algorithm" This reverts commit d8b42751625c915113b64f5a2d9c72f19f009fee. It causes reduced viewport render resolution. Revert for now until I have time to look into this more closely. --- intern/cycles/integrator/render_scheduler.cpp | 28 +++++++++------------------ intern/cycles/integrator/render_scheduler.h | 4 +--- 2 files changed, 10 insertions(+), 22 deletions(-) diff --git a/intern/cycles/integrator/render_scheduler.cpp b/intern/cycles/integrator/render_scheduler.cpp index ec16152d0b9..02e457c2b1b 100644 --- a/intern/cycles/integrator/render_scheduler.cpp +++ b/intern/cycles/integrator/render_scheduler.cpp @@ -1086,8 +1086,14 @@ 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, actual_time_per_update, start_resolution_divider_); + 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. */ /* Never increase resolution to higher than the pixel size (which is possible if the scene is * simple and compute device is fast). */ @@ -1174,14 +1180,12 @@ void RenderScheduler::check_time_limit_reached() * Utility functions. */ -int RenderScheduler::calculate_resolution_divider_for_time(double desired_time, - double actual_time, - int previous_resolution_divider) +int RenderScheduler::calculate_resolution_divider_for_time(double desired_time, double actual_time) { /* 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. @@ -1189,26 +1193,12 @@ 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 705bb3b46ba..28f563c46e3 100644 --- a/intern/cycles/integrator/render_scheduler.h +++ b/intern/cycles/integrator/render_scheduler.h @@ -462,9 +462,7 @@ 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 previous_resolution_divider); + int calculate_resolution_divider_for_time(double desired_time, double actual_time); }; int calculate_resolution_divider_for_resolution(int width, int height, int resolution); -- cgit v1.2.3