Function to change gamma level via C++

Development Programming & Scripting
1

Hello there,

I am currently creating my own custom settings object for saving custom properties such as gameplay relevant stuff and so on. Additionally I just want to let the user choose the desired gamma level of the entire game (e.g. for ■■■■■■ dark screens). I have found the console command

GAMMA float

does that for me. The default value is about 2.2.

But nor I want to implement my “ApplySettings” method in a much more elegant way and I try to avoid calling console commands in my C++ object (which btw inherits from UGameUserSettings class).

Maybe you guys can help me finding the property or setter that I have to use to trigger the change of the gamma level via C++? Any ideas? I do not have any clue where I should start searching. :slight_smile:

Greetings,
Dustin

2

8 years and no one answered… thats some crazy time for such a simple thing to not be answered.

3

Yep, I have the exact same issue and goal.
Did you ever find a solution?

4

You are in luck. Here’s a code snippet for updating a PostProcessVolume’s gamma from C++ code.

This is an actor placed in the world, then given a reference to a PostProcessVolume, which it can control the settings of. It can be used to reasonable simulate dynamic light changes in a baked light map. LightColorType is a custom enum which can be ignored.

The only trick is you have to set the override boolean and change the gamma.

void APPVSettings::UpdatePostProcessVolume(TSoftObjectPtr<APostProcessVolume> ppv, LightColorType type)
{
	if (ppv)
	{
		// time to do some scene color grading and pick what color
		// we will subtly tint the scene based on the light color type
		FVector4 gammaShadows = FVector4(1, 1, 1, 1);
		FVector4 gammaMidtones = FVector4(1, 1, 1, 1);

		if (type == LightColorType::OFF)			{ gammaShadows = FVector4(0.9, 0.9, 0.9, 1.0); gammaMidtones = FVector4(0.9, 0.9, 0.9, 1.0); }
		else if (type == LightColorType::WHITE)		{ gammaShadows = FVector4(1.0, 1.0, 1.0, 1.0); gammaMidtones = FVector4(1.0, 1.0, 1.0, 1.0); }
		else if (type == LightColorType::RED)		{ gammaShadows = FVector4(1.3, 1.0, 1.0, 1.0); gammaMidtones = FVector4(1.1, 1.0, 1.0, 1.0); }
		else if (type == LightColorType::BLUE)		{ gammaShadows = FVector4(1.0, 1.0, 1.3, 1.0); gammaMidtones = FVector4(1.0, 1.0, 1.0, 1.1); }

		// overriding shadow and midtones only with the goal
		// of leaving the bright spaces outside the minimally affected
		ppv->Settings.bOverride_ColorGammaShadows = true;
		ppv->Settings.bOverride_ColorGammaMidtones = true;
		ppv->Settings.ColorGammaShadows = gammaShadows;
		ppv->Settings.ColorGammaMidtones = gammaMidtones;
	}
}