Inject a render pass with a Scriptable Renderer Feature in URP

Use the ScriptableRenderFeature API to insert a Scriptable Render Pass into the Universal Render PipelineA series of operations that take the contents of a Scene, and displays them on a screen. Unity lets you choose from pre-built render pipelines, or write your own. More info
See in Glossary (URP) frame rendering loop.

Follow these steps:

1. Create a new C# script.

2. Replace the code with a class that inherits from the ScriptableRendererFeature class.

   using UnityEngine;
   using UnityEngine.Rendering.Universal;
   
   public class MyRendererFeature : ScriptableRendererFeature
   {
   }
   

3. In the class, override the Create method. For example:

   public override void Create()
   {
   }
   

   URP calls the Create methods on the following events:

   • When the Scriptable Renderer Feature loads the first time.
   • When you enable or disable the Scriptable Renderer Feature.
   • When you change a property in the InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
     See in Glossary window of the Renderer Feature.

4. In the Create method, create an instance of your Scriptable Render Pass, and inject it into the renderer.

   For example, if you have a Scriptable Render Pass called RedTintRenderPass:

   // Define an instance of the Scriptable Render Pass
   private RedTintRenderPass redTintRenderPass;
   
   public override void Create()
   {
       // Create an instance of the Scriptable Render Pass
       redTintRenderPass = new RedTintRenderPass();
   
       // Inject the render pass after rendering the skybox
       redTintRenderPass.renderPassEvent = RenderPassEvent.AfterRenderingSkybox;
   }
   

   You can also use the Create method to initialize any other resources the Scriptable Renderer Feature needs, such as materials.

5. Override the AddRenderPasses method.

   public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
   {
   }
   

   URP calls the AddRenderPasses method every frame, once for each cameraA component which creates an image of a particular viewpoint in your scene. The output is either drawn to the screen or captured as a texture. More info
   See in Glossary. Don’t create or instantiate any resources within this method.

6. Use the EnqueuePass API to inject the Scriptable Render Pass into the frame rendering loop.

   public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
   {
       renderer.EnqueuePass(redTintRenderPass);
   }
   

   To add a render pass to a specific camera only, use an if statement to check the camera type. For example:

   if (renderingData.cameraData.cameraType == CameraType.Game)
   {
       renderer.EnqueuePass(redTintRenderPass);
   }
   

You can now add the Scriptable Renderer Feature to the active URP asset. Refer to How to add a Renderer Feature to a Renderer for more information.

To dispose of any resources, override the Dispose method.

Example

For a complete example of a Scriptable Renderer Feature with a custom render pass that uses a material to blitA shorthand term for “bit block transfer”. A blit operation is the process of transferring blocks of data from one place in memory to another.
See in Glossary, follow these steps:

1. Import the URP render graph samples. For more information, refer to Importing a package sample in URP.
2. In the Project window, go to Samples > Universal Render Pipeline > <your version> > URP RenderGraph Samples > BlitWithMaterial.

Additional resources

• ScriptableRendererFeature
• Add a Renderer Feature to a URP Renderer
• Restrict a render pass to a scene area
• Create a custom post-processing effect with Volume support in URP
• Custom render pass workflow in URP
• Render graph system