Depth API Material Graph

The Environment Depth material expression lets you sample the depth texture directly in your material graph. Depth is returned in world units (centimeters by default). The Environment Depth expression functions similarly to SceneDepth⁠ as a material expression that returns a per-pixel depth value. However, SceneDepth returns the depth of rendered virtual geometry from the scene’s Z-buffer, while Environment Depth returns real-world distance estimated by the headset’s stereo cameras and depth estimation system.

Note: The Environment Depth material expression node is only available in the Meta fork of the Unreal Engine. If you are using the stock engine, this node is not available and materials referencing it display as solid red. The basic Depth API features, such as StartEnvironmentDepth and occlusion modes, work with the standard Meta XR Plugin.

Before using the Environment Depth material expression, ensure you have the following:

The following examples demonstrate additional use cases beyond occlusion.

The first example gets the environment depth and maps it to the hue of a color, visualizing depth as a color gradient. The Environment Depth output connects to a hue mapping node, so the rendered color shifts continuously based on the estimated distance from the headset’s depth estimation system.

The second example gets the environment depth and scene depth and compares the distance. An if-condition node compares the Environment Depth and SceneDepth outputs: if the environment depth is greater than the scene depth, the material renders red; otherwise it renders blue.

The following Blueprint-callable functions are available in UOculusXRFunctionLibrary for controlling the depth texture:

For a complete working implementation, see the Unreal-OcclusionSample⁠.