Ray-Traced Contact Shadows

Ray-Traced Contact Shadows is a ray tracing feature in the High Definition Render Pipeline (HDRP). It is an alternative to HDRP's Contact Shadow technique that uses a more accurate ray-traced solution that can use off-screen data.

Without Contact shadows

Contact shadows

Ray-traced contact shadows

For information about ray tracing in HDRP, and how to set up your HDRP Project to support ray tracing, see Getting started with ray tracing.

Using Ray-Traced Contact Shadows

Because this feature is an alternative to the contact shadows Volume Override, the initial setup is very similar.

  1. Enable contact shadows in your HDRP Asset.
  2. Enable contact shadows for your Cameras.
  3. Add the effect to a Volume in your Scene.

HDRP Asset setup

The HDRP Asset controls which features are available in your HDRP Project. To make HDRP support and allocate memory for contact Shadows:

  1. Click on your HDRP Asset in the Project window to view it in the Inspector.
  2. In the Lighting > Shadows section, enable Contact Shadows.

Camera setup

Cameras use Frame Settings to decide how to render the Scene. To enable contact shadows for your Cameras by default:

  1. Open the Project Settings window (menu: Edit > Project Settings), then select the HDRP Default Settings tab.
  2. Select Camera from the Default Frame Settings For drop-down.
  3. In the Lighting section, enable Contact Shadows.

All Cameras can now process contact shadows unless they use custom Frame Settings. If they do:

  1. In the Scene view or Hierarchy, select the Camera's GameObject to open it in the Inspector.
  2. In the Custom Frame Settings, navigate to the Lighting section and enable Contact Shadows.

Volume setup

Ray-Traced Contact Shadow uses the Volume framework, so to enable this feature and modify its properties, you need to add an Contact Shadow override to a Volume in your Scene. To do this:

  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 on Conact Shadows. HDRP now applies contact shadow to any Camera this Volume affects.

Light Setup

To make HDRP calculate, and use, Ray-Traced Contact Shadows, you need to enable them on a Light .

  1. In your Light component, go to Shadows > Contact Shadows and tick the Enable checkbox. This exposes the Ray Tracing property.
  2. Enable the Ray Tracing checkbox.