URP Skeleton Lit + Slot color not working in 4.1 or 4.2

valorware

Hi. When using colors on Slots, or changing the slot color at runtime using slot.SetColor(...), the colors are not visible. If it switch the material to Skeleton (unlit), the colors are perfectly visible, which leads me to believe this is a bug rather than setup error? This is SkeletonAnimation, Not UI. I'm really in crunch at the moment so im unable to do extensive testing, sorry. I have z-spacing enabled, I am using Forward+ but a quick test in deferred and Forward seemed to not fix it.

Give step-by-step instructions so we can reproduce the problem, if possible.
Add a color to any slot, make it bright red or something. Export to unity and set the material to URP->Skeleton Lit. Hopefully observe the missing color.

Runtime information

Various 4.1 and 4.2, Unity 2022.3.14f1

Spinebot

It seems like you are encountering an issue with the Skeleton Lit shader in URP where slot colors are not visible. This issue has been reported and addressed in various contexts. Here are some steps and checks you can follow to troubleshoot and potentially resolve the issue:

Ensure Correct Shader Version:
- Make sure you are using the latest version of the Spine URP shaders. You can download the latest 4.1 and 4.2-beta Spine URP Shaders UPM packages from here.
Check Shader Settings:
- Verify that you are using the correct shader. The shader should be Universal Render Pipeline/Spine/Skeleton Lit.
- Ensure that PMA Vertex Colors is enabled in the SkeletonAnimation component.
Project Settings:
- Check your project settings under Project Settings -> Quality to ensure that the correct 2D Render Pipeline Asset is assigned.
Forward+ Renderer:
- If you are using the Forward+ renderer, ensure that the Spine URP shaders support it. The latest versions should support Forward+ as mentioned here.
Minimal Reproduction Project:
- If the issue persists, consider creating a minimal Unity project that demonstrates the problem. This can help in identifying if there is a specific setup issue or a bug. You can send this project to the support team for further investigation.
Bug Fixes:
- There have been recent bug fixes related to the Skeleton Lit shader. Ensure you have the latest updates from the 4.2 branch, which you can download from the same link provided above.

Here is a step-by-step guide to reproduce the problem and verify the solution:

Create a New Spine Project:
- Add a color to any slot, making it bright red or another noticeable color.
- Export the project to Unity.
Set Up in Unity:
- Import the exported Spine project into Unity.
- Assign the Universal Render Pipeline/Spine/Skeleton Lit shader to the material.
Check Visibility:
- Observe if the slot colors are visible. If not, proceed with the troubleshooting steps mentioned above.

If the issue persists after following these steps, it might be a bug that needs further investigation. In that case, providing a minimal reproduction project to the support team would be the best course of action.

valorware

Sadly the steps from the Spinebot did not help. I already had PMA Vertex colors enabled (I also have add normals enabled) and I've tried with 4.1 and the latest 4.2

Harald

@valorware Sorry to hear you're having troubles! Unfortunately we couldn't reproduce the issue, everything displayed as expected on our end.

Please be sure to test with the latest spine-unity 4.2 runtime and the latest 4.2 Spine URP Shaders UPM package from the download page.

Also be sure you're using the Universal Render Pipeline/Spine/Skeleton Lit shader and not a shader of similar name. As a last resort, another point to check is whether perhaps there are any stray keywords active at the Material from previous different shaders. Normally those should not cause any issues, however the small chance exists that there are some hidden side-effects. To start without stray keywords, Reset the Material in the Inspector via the Material context-menu and reassign the texture and other desired properties.

If the issue persists, you can send us a minimal Unity project as a zip package to contact@esotericsoftware.com, briefly mentioning this forum thread URL so that we know the context. Then we can have a look at it.