Screen Space Refraction

The Screen Space Refraction (SSR) override is a High Definition Render Pipeline (HDRP) feature that uses the depth and color buffer of the screen to calculate refraction. For information about how screen space refraction works in HDRP, see the Screen space refraction documentation.

Using Screen Space Refraction

HDRP uses the Volume framework to calculate SSR, so to enable and modify SSR properties, you must add a Screen Space Refraction override to a Volume in your Scene. To add Screen Space Refraction to a Volume:

1. In the Scene or Hierarchy view, select a GameObject that contains a Volume component to view it in the Inspector.
2. In the Inspector, navigate to Add Override > Lighting and click Screen Space Refraction. HDRP now calculates SSR for any Camera this Volume affects.

API

To access and control this override at runtime, use the Volume scripting API. Because of how the Volume system works, you edit properties in a different way to standard Unity components. There are also other nuances to be aware of too, such as each property has an overrideState. This indicates to the Volume system whether to use the property value you set, or use the default value stored in the Volume Profile. For information on how to use the API correctly, see Volume scripting API.

Properties

To edit properties in any Volume component override, enable the checkbox to the left of the property. This also tells HDRP to use the property value you specify for the Volume component rather than the default value. If you disable the checkbox, HDRP ignores the property you set and uses the Volume’s default value for that property instead.

Property	Description
Screen Edge Fade Distance	Use the slider to control the distance at which HDRP fades out the refraction effect when the destination of the ray is near the boundaries of the screen. Increase this value to increase the distance from the screen edge at which HDRP fades out the refraction effect for a ray destination.