Problem with texture not being visible when outline is enabled in Unity 6

MK82

Hello. I am using Spine version 4.2 in Unity. Until now, I was using Unity 2022.3 and all the functions of Spine were working normally. However, this time, when I used Unity 6, an issue related to the outline occurred. When I enable the outline of Spine in Unity 6, only the outline is visible and the texture inside the outline is not visible.

Basic texture

Enabling the outline

When the same asset was imported in a version before Unity 6, the outline shader worked normally. I tested it with version 4.3 because I thought it might have been resolved in version 4.3, but the same problem occurred.

I confirmed that if I disable the outline pass in the outline shader, it looks like a normal shader without the outline. However, I don't know enough about shaders to know how to fix this. Is there anyone who is having the same problem?

Misaki

MK82 If your project is a URP project, the section titled “The Outline shader displays only outlines in my URP project. Why?” in the FAQ page of the documentation may be helpful. If that is the case, you do not need to modify the shader yourself.

Spinebot

It seems like the issue you're experiencing with the outline shader in Unity 6 might be related to the shader settings or the rendering order. In previous versions, the outline shader might have been configured to render correctly, but changes in Unity 6 could have affected how the shader interacts with the rendering pipeline. One potential solution is to ensure that the Fill property in the outline shader is enabled, which can help fill any transparent gaps between the outline and the skeleton. This property was introduced to address similar issues with transparency gaps. Additionally, you might want to check if the outline shader is set to render behind the main texture by adjusting the Z offset or render order, as suggested in the context. If these adjustments don't resolve the issue, you may need to look into the shader code to ensure compatibility with Unity 6's rendering changes.

MK82

Misaki Thank you! My current project is using built-in shaders. However, the link you attached shows the same issue. I'll have to think about whether URP and Unity 6 have the same cause.

MK82

Misaki It was a really simple and pathetic problem. When I create a project in Unity, I always create a 2D project at the top without much thought. However, up to version 2022.3, the built-in project is at the top, but from Unity 6, the URP project is at the top. I thought it was a project created as built-in, but when I checked again, it was created as URP. When I checked again by creating it as a built-in project, the outline shader works normally.

If you hadn't given me a hint about URP, I would have continued to think this project was using the built-in shader. Thank you for helping me solve the problem.

Misaki

MK82 I'm glad you figured out the cause! Thank you for getting back to us! 🙂