You can use certain tone mapping effects in Unreal Engine on Meta Quest without incurring the traditional performance cost associated with tone mapping. The Meta Quest integration can render tone mapping with as little as 600 microseconds of additional render time because it uses Vulkan subpasses instead of Unreal Engine’s Mobile HDR mode or an additional render pass. This feature is only available in the Oculus-VR fork of UE using Vulkan.

The Vulkan Tonemap Subpass supports the following post process effects:

Color Grading (includes LUT)

Filmic Tonemapping

Vignette

Android Vulkan Preview is supported in editor.

Samples

The Graphics Showcase example demonstrates these common tone mapping effects:

Fade In / Fade Out

Color Tint Day-Night Cycle

Color Grading LUT

Vignette

The Graphics Showcase sample app is available on:

Github

Meta Horizon Store

Enabling Subpasses for Tone Mapping

To enable the Vulkan subpasses for tone mapping, set r.Mobile.TonemapSubpass=1.

To disable the Vulkan subpasses to regain performance when tone mapping is not needed, set r.Mobile.TonemapSubpass=0.

Tone Mapping Effects

You can implement specific tone mapping effects by changing values in the Post Process Volume properties and the Level Sequence. Specifically, we’ve implemented Vulkan subpass support for:

Fade tracks in the Level Sequence

Scene Color Tint in the Post Process Volume properties

Color Grading LUT in the Post Process Volume properties

Vignettes in the Post Process Volume properties

Fade In and Fade Out

You can implement fade in and fade out effects by adding a Fade track to the Level Sequence and defining key points on the Fade track. A fade value of 1.0 is fully opaque black and 0.0 is fully transparent.

To implement a fade:

From the main toolbar, click Cinematics > Add Level Sequence.

In the Sequencer, click + Track, and then select Fade Track.

Select the Fade track, and click o to add keyframes.

Color Tint

You can add a color tint or tone by adding a Post Process Volume and changing the Scene Color Tint properties of the volume.

To add a basic color tint:

Add a Post Process Volume actor to your level.

Go to Post Process Volume Settings properties, and then select Enabled and Infinite Extent (Unbound).

Set the Color Grading|Misc > Scene Color Tint properties to the color tint you want.

Post Process Volume scene color tint settings

Day and Night Cycle

You can animate a day and night cycle by using the sequencer to gradually change the color tint of the Post Process Volume over time. For example, you can make the Scene Color Tint gradually change from blue at night, to red at dawn to neutral white by day.

To create a sequence of Scene Color Tint property changes:

From the main toolbar, click Cinematics > Add Level Sequence.

In the Sequencer, click + Track > Actor to Sequencer and then select your post process volume. Your post process volume is added to the sequencer.

In the post process volume added to the sequencer, click + Track > Settings > Color Grading|Misc > Scene Color Tint. The scene color tint setting is added to the sequencer.

Expand Scene Color Tint (Settings), and then click o to add keyframes where you want them.