Temporal Pixel Synthesis

Understand how to enable and configure Temporal Pixel Synthesis in your Unity project.

Temporal Pixel Synthesis (TPS) is an image-quality feature for Meta Quest devices that lets the Meta runtime apply temporal anti-aliasing, upscaling, or other temporal reconstruction techniques to the current frame. Your application supplies per-view motion vector data each frame so the runtime can accurately track pixel movement between frames. Depth and stencil data are also used when available.

Prerequisites

To use TPS, your project must meet the following requirements:

  • Unity 6 or newer
  • Unity OpenXR plugin (com.unity.xr.openxr) with a runtime that supports the XR_META_temporal_pixel_synthesis extension.
  • Universal Render Pipeline (URP)
  • Android build target (Meta Quest)
  • Use the Vulkan API. This feature isn't available on other graphics APIs. To understand how to choose your graphics API, refer to Configure graphics APIs.
Note

If your application runs on any other graphics API, TPS logs an error and is disabled. Your application continues to run without it.

Compatibility

Avoid the following settings with TPS:

  • URP upscaling filter: Set the URP Asset's Upscaling Filter to Automatic. Using any other upscaling filter alongside TPS can degrade performance.
  • Multisample anti-aliasing (MSAA): Set the URP Asset's Anti Aliasing (MSAA) property to Disabled. Using MSAA alongside TPS can degrade performance.
  • Per-camera anti-aliasing: In the Rendering section of each Camera component, set Anti-aliasing to No Anti-aliasing. This setting is separate from the URP Asset's Anti Aliasing (MSAA) property. The Meta runtime performs the temporal resolve, so URP's anti-aliasing is redundant and its jitter reduces image quality.

The validation rule for this setting only checks cameras in scenes that are currently open, so verify any cameras you load or instantiate at runtime.

Enable Temporal Pixel Synthesis

To enable TPS in your project:

  1. Open the Project Settings window (menu: Edit > Project Settings).
  2. Under XR Plug-in Management, select the OpenXR settings.
  3. Under OpenXR Feature Groups, enable the Meta: Temporal Pixel Synthesis feature.

When your application starts, the Meta runtime begins pixel synthesis with the default parameters, so no additional scripting is required. To change those defaults, refer to the settings in the following section.

Temporal Pixel Synthesis settings

Use the following settings to configure Temporal Pixel Synthesis:

Setting Description
Default Fovea Quality Quality hint for the central (fovea) region of pixel synthesis. Defaults to High.
Default Periphery Quality Quality hint for the outer (periphery) region of pixel synthesis. Defaults to Medium.
Default Fovea Radius Radius hint controlling the boundary between the high-quality central region and the periphery. Defaults to Medium.
Default Enable Upscaling Whether to request upscaling as part of pixel synthesis. Requires PixelSynthesisSupportedFeatureFlags.Upscaling. Defaults to disabled.
Default Upscaling Quality Quality hint for upscaling. Only used when Default Enable Upscaling is enabled. Defaults to Medium.

Quality levels

The fovea quality, periphery quality, and upscaling quality settings all use the PixelSynthesisQualityLevel enum. The following table lists the available values.

Value Description
Disabled No temporal accumulation for this region.
Low Prioritizes performance over quality.
Medium Balances performance and quality.
High Prioritizes quality over performance.
Dynamic The runtime dynamically adjusts quality based on headroom. Requires PixelSynthesisSupportedFeatureFlags.DynamicQuality.

Fovea radius

The PixelSynthesisFoveaRadius enum controls the size of the high-quality central region:

Value Description
Small Small fovea region — prioritizes performance.
Medium Medium fovea region — balances performance and quality.
Large Large fovea region — prioritizes quality.
Dynamic The runtime dynamically varies the radius. Requires PixelSynthesisSupportedFeatureFlags.DynamicQuality.

Use Temporal Pixel Synthesis at runtime

Call MetaTemporalPixelSynthesisFeature.SetPixelSynthesis to supply custom parameters:

Method Description
SetPixelSynthesis Sets pixel synthesis parameters. Cached and reused every frame until called again.
ClearPixelSynthesis Resets parameters to their defaults without disabling pixel synthesis.
SetPixelSynthesisEnabled Enables or disables pixel synthesis at runtime. Cached parameters are preserved and resume when re-enabled.

Frame parameters

Start from PixelSynthesisFrameParams.Default to get the default values in the following table. A default-constructed PixelSynthesisFrameParams leaves nearZ and farZ at 0, which SetPixelSynthesis treats as an explicit near and far plane instead of reading Camera.main.

Field Type Description
motionVectorScale Vector2 Per-axis scale applied to motion vector texel values to convert to normalized device coordinates (NDC). The Y axis is negative because the compositor expects the opposite vertical convention to the render pipeline's output. Default: new Vector2(1f, -1f).
motionVectorOffset Vector2 Per-axis offset applied to motion vector texel values to convert to NDC. Default: Vector2.zero.
appSpaceDeltaPosition Vector3 Position delta of the app space between frames. Set to Vector3.zero when no artificial locomotion occurs.
appSpaceDeltaOrientation Quaternion Orientation delta of the app space between frames. Set to Quaternion.identity when no artificial locomotion occurred.
nearZ float Near clip distance in meters. A negative value makes SetPixelSynthesis read the value from Camera.main.nearClipPlane, or use 0.1 if the scene has no main camera. Default: -1.
farZ float Far clip distance in meters. A negative value makes SetPixelSynthesis read the value from Camera.main.farClipPlane, or use 1000 if the scene has no main camera. Default: -1.
stencilBitMask uint Bitmask of stencil bits to compare. Set to 0 to omit stencil masking.
stencilValue uint Reference stencil value. Pixels where (stencilBuffer & stencilBitMask) == stencilValue are excluded from temporal accumulation.
resetAggregations bool When true, the runtime discards all accumulated temporal state and starts fresh. Set this field to true on scene transitions, camera cuts, or teleportation.
enableUpscaling bool Whether to request upscaling for this frame. Overrides the Default Enable Upscaling setting. Requires runtime support for PixelSynthesisSupportedFeatureFlags.Upscaling. Default: false.

Additional resources