Render Z / with transparent object and screen depth shaders

Fattori

I am using Spine 4.3 unity plugin, and we have particle system emitting transparent particles, however it always gets covered by our Spine objects (with Spine/Skeleton shader applied) , we tried changing the render order/ and render queue , however it keeps messing with other objects in the scene, its always either on top of behind, i wish there was another way to deal with it.

Spinebot

To address the issue of Spine objects covering transparent particles in Unity, you can consider a few approaches. First, ensure that the Z-Spacing parameter in the SkeletonRenderer or SkeletonGraphic component is set to a value other than 0 to prevent Z-fighting when using depth writing. Additionally, you might need to adjust the Depth alpha cutoff value if you have Write to Depth enabled, as a low value can cause semi-transparent areas to block subsequent overlaid pixels. If these adjustments do not resolve the issue, you may need to modify the draw order by changing the render queue or using a custom shader that better handles transparency and depth. Keep in mind that using the depth buffer with semi-transparent objects can lead to trade-offs, and sometimes rendering to a render texture first can be a more effective solution for complex scenes with overlapping transparency.

Fattori

This wont solve our problem because its not about going on top or under other elements but interacting with it properly.

i added a fake depth fog to some elements that had to interact with a depth fog, but idk if this is the best practice, some fullscreen shaders are also drawing behind the spine objects.

Any solution?

Harald

@Fattori The default spine-unity shaders use the Transparent render queue and don't render to the z-buffer, as Spine skeletons are usually semi-transparent objects at the border of each attachment image (gradually fading alpha out from 1.0 to 0.0). The same applies to particles, they are semi-transparent objects which are also using the Transparent render queue.

If you now need to interleave both the Spine skeleton and particle effects, the Spine skeleton needs to write to the z-buffer. Otherwise a skeleton drawn with a single draw-call won't magically interleave itself with particles, this would only happen when having 10 objects for the skeleton and 10 objects for particles, all rendered and sorted separately. Thus you have to enable Depth Write or ZWrite at the used Spine shader (or use z-write variant of a shader) and modify the render queue value (at the Material, or modify a copy of the shader) before your particle effects (which never write to the depth buffer). This ensures that any particle effects, which use only depth-testing but no depth-write, have the proper depth information available to work with.