Currently, rendering Spine sprites in a 3D space within Godot 4 is not directly supported through the official Spine runtimes. There is an open issue ticket for this as a future enhancement (#2135). A workaround that has been mentioned involves rendering each SpineSprite to an off-screen render target, which could potentially impact performance if you have a large number of skeletons on screen. This method is not ideal and could significantly stall the GPU pipeline. Additionally, there's a mention of using a 3D hack with Mesh3D + Texture from SubViewport, but this approach is also not recommended due to performance issues. The Spine team has acknowledged the demand for a SpineSprite3D but has prioritized other developments at the moment.
For now, the best approach to integrate Spine animations into a 3D scene in Godot 4 would be to follow the progress on the official issue tracker and experiment with the mentioned workarounds, keeping in mind the potential performance implications.
