r.Test.SecondaryUpscaleOverride

r.Test.SecondaryUpscaleOverride

#Overview

name: r.Test.SecondaryUpscaleOverride

This variable is created as a Console Variable (cvar).

• type: Var
• help: Override the secondary upscale.\n 0: disabled; (default)\n 1: use secondary view fraction = 0.5 with nearest secondary upscale.

It is referenced in 3 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of r.Test.SecondaryUpscaleOverride is to provide a testing mechanism for overriding the secondary upscale in Unreal Engine’s rendering system.

• This setting variable is primarily used by the rendering system, specifically for testing and debugging purposes related to screen percentage and upscaling.

• The Unreal Engine subsystem that relies on this setting variable is the renderer, as evidenced by its location in the SceneRendering.cpp file within the Runtime/Renderer module.

• The value of this variable is set through the console variable system (CVarTestSecondaryUpscaleOverride) with a default value of 0, meaning it’s disabled by default.

• This variable interacts with ViewFamily.SecondaryViewFraction and ViewFamily.SecondaryScreenPercentageMethod. When enabled, it overrides these properties to test different secondary upscale configurations.

• Developers must be aware that this is a testing variable and should not be used in production environments. It’s designed for debugging and performance testing purposes only.

• Best practices when using this variable include:

  1. Only enable it in non-shipping builds for testing purposes.
  2. Be cautious when using it, as it can significantly affect rendering performance and quality.
  3. Always reset it to 0 after testing to ensure it doesn’t interfere with normal rendering.

Regarding the associated variable CVarTestSecondaryUpscaleOverride:

• This is the actual console variable that controls the r.Test.SecondaryUpscaleOverride setting.
• It’s defined as an integer with three possible values: 0: Disabled (default) 1: Use secondary view fraction = 0.5 with nearest secondary upscale
• It’s used in the FSceneRenderer constructor to override the SecondaryViewFraction and SecondaryScreenPercentageMethod when enabled.
• Developers should use this console variable to toggle the secondary upscale override for testing, rather than directly modifying the r.Test.SecondaryUpscaleOverride value.

#References in C++ code

#Callsites

This variable is referenced in the following C++ source code:

#Loc: <Workspace>/Engine/Source/Runtime/Renderer/Private/SceneRendering.cpp:412

Scope: file

Source code excerpt:

static TAutoConsoleVariable<int32> CVarTestSecondaryUpscaleOverride(
	TEXT("r.Test.SecondaryUpscaleOverride"),
	0,
	TEXT("Override the secondary upscale.\n")
	TEXT(" 0: disabled; (default)\n")
	TEXT(" 1: use secondary view fraction = 0.5 with nearest secondary upscale."));

#endif

#Associated Variable and Callsites

This variable is associated with another variable named CVarTestSecondaryUpscaleOverride. They share the same value. See the following C++ source code.

#Loc: <Workspace>/Engine/Source/Runtime/Renderer/Private/SceneRendering.cpp:411

Scope: file

Source code excerpt:

	TEXT(" 2: TemporalAA upsample."));

static TAutoConsoleVariable<int32> CVarTestSecondaryUpscaleOverride(
	TEXT("r.Test.SecondaryUpscaleOverride"),
	0,
	TEXT("Override the secondary upscale.\n")
	TEXT(" 0: disabled; (default)\n")
	TEXT(" 1: use secondary view fraction = 0.5 with nearest secondary upscale."));

#Loc: <Workspace>/Engine/Source/Runtime/Renderer/Private/SceneRendering.cpp:2795

Scope (from outer to inner):

file
function     FSceneRenderer::FSceneRenderer

Source code excerpt:

	// Override secondary screen percentage for testing purpose.
	if (CVarTestSecondaryUpscaleOverride.GetValueOnGameThread() > 0 && !ViewFamily.Views[0]->bIsReflectionCapture)
	{
		ViewFamily.SecondaryViewFraction = 1.0 / float(CVarTestSecondaryUpscaleOverride.GetValueOnGameThread());
		ViewFamily.SecondaryScreenPercentageMethod = ESecondaryScreenPercentageMethod::NearestSpatialUpscale;
	}
#endif

	// If any viewpoint has been locked, set time to zero to avoid time-based
	// rendering differences in materials.