UnityCACAO-HDRP17/com.unity.render-pipelines.high-definition/Documentation~/custom-post-processing-use-full-screen-shader.md

Use a full-screen shader with a custom post-processing volume

You can use HDRP’s Fullscreen Master Stack to create a full-screen shader that you can use in a custom post-processing effect. This means you don’t need to write any shader code.

To use a full-screen shader with a custom post-processing volume:

1. In the Project window, select the full-screen shader graph to view it in the Inspector.
2. Find the name and subcategory of the fullscreen shader. For example ShaderGraphs/Fullscreen_PostProcess
3. In the Project window, double-click the custom post-processing volume script to open it in a script editor.
4. In the custom post-processing volume script, find the following line that defines the name and subcategory of the shader the volume uses:

 const string kShaderName = "Hidden/Shader/NewPostProcessVolume";

5. Replace Hidden/Shader/NewPostProcessVolume with the name and subcategory of the fullscreen shader you want to use in this custom post-processing effect. For example:

const string kShaderName = "ShaderGraphs/Fullscreen_PostProcess";