Color Mapping Techniques

• None: Display passthrough images unchanged.
• Color Adjustment: Adjust the image’s brightness, contrast, and saturation. Saturation adjustment only has an effect on devices that support color passthrough.
• Grayscale: Adjust brightness and contrast and apply a posterization effect to grayscale passthrough images. Color passthrough images are converted to grayscale first if this option is chosen.
• Grayscale To Color: Colorize grayscale passthrough images, adjust brightness and contrast, and apply a posterization effect. Color passthrough images are converted to grayscale first if this option is chosen.
• Color LUT: Apply a color look-up table (LUT), which maps each RGB input color into an arbitrary RGB(A) in the passthrough image stream.
• Blended Color LUTs: Apply the blend between two color LUTs to the passthrough image stream. This option can be used to smoothly transition between two color LUTs.

1. In the OVRPassthroughLayer component, under Color Control, select Color LUT.
2. Under LUT, select a 2D texture that represents a color LUT. See Creating Color LUTs for more information on supported formats and how to generate them.
3. Check Flip Vertically if the LUT has black (RGB values 0, 0, 0) in the top-left corner of the texture, otherwise uncheck it.
4. The Blend slider controls the mix between the original and the replacement color. Leave it at 1 to fully apply the LUT.

1. Create an instance of OVRPassthroughColorLut. The LUT data can be passed as a 2D texture or as 3D array of color values. Refer to the API reference for all constructor signatures.
2. Call SetColorLut on the instance of OVRPassthroughLayer the color LUT should be applied to, passing the OVRPassthroughColorLut instance as the first parameter. The weight parameter corresponds to the Blend value specified in the inspector.
3. Optionally, you can apply an OVRPassthroughColorLut instance to multiple passthrough layers by passing it to SetColorLut calls on multiple layers.

public class PassthroughColorLUTController : MonoBehaviour
{
    Private Texture2D _2dColorLUT;
    OVRPassthroughColorLut ovrpcl;

    // other code...

    GameObject ovrCameraRig = GameObject.Find("OVRCameraRig");
    passthroughLayer = ovrCameraRig.GetComponent<OVRPassthroughLayer>();
    ovrpcl = new OVRPassthroughColorLut(_2dColorLUT, false);
    passthroughLayer.SetColorLut(ovrpcl, 1);
}

SetColorLut(lut, weight)

SetColorLut(lutSource, lutTarget, weight)

• There is a constraint on the maximum resolution allowed for color LUTs, which can be queried using OVRManager.GetPassthroughCapabilities. On current Meta Quest devices, the maximum resolution is 64.
• The color LUT resolution impacts memory usage and GPU performance. For that reason, it is advisable to keep the resolution as small as possible given use case and quality constraints. For example, start with a color LUT of resolution 16, then check if increasing the resolution to 32 significantly improves the visual quality.
• For high-resolution color LUTs (especially 64), constructing an OVRPassthroughColorLut object can take a few milliseconds and is best done in advance.
• OVRPassthroughColorLut instances occupy an amount of memory that is proportional to the LUT data size. Dispose can be called to free the memory immediately.
• An instance of OVRPassthroughColorLut can be applied to multiple passthrough layers by passing it to SetColorLut on multiple layers. Doing so reduces the memory usage (compared to creating a separate OVRPassthroughColorLut instance per layer).