r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution

r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution

#Overview

name: r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution

The value of this variable can be defined or overridden in .ini config files. 3 .ini config files referencing this setting variable.

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

It is referenced in 3 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution is to control the resolution of the probe’s 2D radiance layout in Lumen’s Translucency Volume Radiance Cache system. This setting is part of Unreal Engine 5’s rendering system, specifically the Lumen global illumination solution.

This setting variable is primarily used by the Lumen subsystem within the Renderer module of Unreal Engine 5. It’s specifically related to the Translucency Volume lighting calculations, which are part of Lumen’s global illumination system.

The value of this variable is set through the console variable system, as indicated by the FAutoConsoleVariableRef declaration. It can be modified at runtime using console commands or through project settings.

The associated variable GTranslucencyVolumeRadianceCacheProbeResolution directly interacts with this setting. They share the same value, with GTranslucencyVolumeRadianceCacheProbeResolution being the actual variable used in the code, while r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution is the console variable name used for setting and accessing this value.

Developers must be aware that this variable affects the quality and performance of translucency lighting in scenes using Lumen. The resolution set by this variable determines the number of rays traced for each probe, which is calculated as ProbeResolution^2. Higher values will result in more accurate lighting but at the cost of increased performance overhead.

Best practices when using this variable include:

  1. Balancing quality and performance based on the specific needs of the project.
  2. Considering the target hardware capabilities when setting this value.
  3. Testing different values to find the optimal balance between visual quality and performance for each specific use case.

Regarding the associated variable GTranslucencyVolumeRadianceCacheProbeResolution:

The purpose of GTranslucencyVolumeRadianceCacheProbeResolution is to store and provide access to the probe resolution value within the C++ code of the Lumen system.

This variable is used directly in the Lumen Translucency Volume lighting calculations, specifically in the LumenTranslucencyVolumeRadianceCache namespace.

The value of this variable is set by the console variable system, mirroring the value of r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution.

It interacts directly with the console variable and is used in calculations to determine the number of rays to trace for each probe.

Developers should be aware that modifying this variable directly in code is not recommended, as it should be controlled through the console variable system for consistency.

Best practices include accessing this variable through the provided getter function GetProbeResolution() within the LumenTranslucencyVolumeRadianceCache namespace, rather than accessing it directly, to ensure proper encapsulation and potential future flexibility.

#Setting Variables

#References In INI files

Location: <Workspace>/Engine/Config/BaseScalability.ini:289, section: [GlobalIlluminationQuality@2]

Location: <Workspace>/Engine/Config/BaseScalability.ini:313, section: [GlobalIlluminationQuality@3]

Location: <Workspace>/Engine/Config/BaseScalability.ini:337, section: [GlobalIlluminationQuality@Cine]

#References in C++ code

#Callsites

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

#Loc: <Workspace>/Engine/Source/Runtime/Renderer/Private/Lumen/LumenTranslucencyVolumeLighting.cpp:196

Scope: file

Source code excerpt:

int32 GTranslucencyVolumeRadianceCacheProbeResolution = 8;
FAutoConsoleVariableRef CVarTranslucencyVolumeRadianceCacheProbeResolution(
	TEXT("r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution"),
	GTranslucencyVolumeRadianceCacheProbeResolution,
	TEXT("Resolution of the probe's 2d radiance layout.  The number of rays traced for the probe will be ProbeResolution ^ 2"),
	ECVF_Scalability | ECVF_RenderThreadSafe
);

int32 GTranslucencyVolumeRadianceCacheProbeAtlasResolutionInProbes = 128;

#Associated Variable and Callsites

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

#Loc: <Workspace>/Engine/Source/Runtime/Renderer/Private/Lumen/LumenTranslucencyVolumeLighting.cpp:194

Scope: file

Source code excerpt:

);

int32 GTranslucencyVolumeRadianceCacheProbeResolution = 8;
FAutoConsoleVariableRef CVarTranslucencyVolumeRadianceCacheProbeResolution(
	TEXT("r.Lumen.TranslucencyVolume.RadianceCache.ProbeResolution"),
	GTranslucencyVolumeRadianceCacheProbeResolution,
	TEXT("Resolution of the probe's 2d radiance layout.  The number of rays traced for the probe will be ProbeResolution ^ 2"),
	ECVF_Scalability | ECVF_RenderThreadSafe
);

int32 GTranslucencyVolumeRadianceCacheProbeAtlasResolutionInProbes = 128;
FAutoConsoleVariableRef CVarTranslucencyVolumeRadianceCacheProbeAtlasResolutionInProbes(

#Loc: <Workspace>/Engine/Source/Runtime/Renderer/Private/Lumen/LumenTranslucencyVolumeLighting.cpp:288

Scope (from outer to inner):

file
namespace    LumenTranslucencyVolumeRadianceCache
function     int32 GetProbeResolution

Source code excerpt:

	int32 GetProbeResolution()
	{
		return GTranslucencyVolumeRadianceCacheProbeResolution;
	}

	int32 GetNumMipmaps()
	{
		return GTranslucencyVolumeRadianceCacheNumMipmaps;
	}