Several factors could be behind the error where a Shader Graph in Unity's High Definition Render Pipeline (HDRP) is not working correctly. Here are some potential causes:
Compatibility Issues: The version of Unity or HDRP package might not be compatible with the Shader Graph feature.
Shader Graph Updates: Shader Graph may have received an update that requires changes to existing graphs or settings.
Incorrect Configuration: HDRP assets and the project settings might not be configured correctly for Shader Graphs to function.
Broken Nodes or Connections: There may be nodes within the Shader Graph that are not connected properly or that are incompatible with HDRP.
Graphics API Limitations: The graphics API selected in your project settings might not support some of the features used in the Shader Graph.
Shader Compilation Errors: Errors within the Shader Graph can prevent proper compilation, which leads to it not working as expected.
Solution - Here's How To Resolve It
To resolve issues with Shader Graph not working in HDRP, consider the following solutions:
Check Compatibility: Ensure that you're using a version of Unity and HDRP that supports Shader Graph. Refer to the official documentation for compatibility guidelines.
Update Shader Graph: If there are updates available for Shader Graph, apply them. After updating, check if existing graphs require any adjustments.
Review Configuration: Verify that the HDRP asset settings are correct and that the project is set up for HDRP use. Check the Graphics, Quality, and Project settings to make sure they align with the requirements for HDRP and Shader Graph.
Inspect Nodes: Open the Shader Graph and look for any broken nodes or connections. Make sure each node has the proper inputs and outputs connected.
Change Graphics API: If the problem is related to the Graphics API, switch to a different one that is supported by HDRP and Shader Graph. This is done via the Player settings in Unity.
Debug Shader Graph: Look for any error messages in the Unity Console when trying to compile the Shader Graph. Resolving these errors may fix the issue.
Reimport Shader Graph Asset: Sometimes, reimporting the Shader Graph asset can fix issues caused by corruption or failed imports.
Create a New Shader Graph: As a last resort, try creating a new Shader Graph from scratch and see if the problem persists. If the new graph works, migrate the nodes from the old graph to the new one.
If none of these solutions work, consider seeking help from the Unity community forums or submitting a bug report to Unity for further assistance.