Various fixes to UV2 unwrapping and the GPU lightmapper. Listed here for
context in case of git blame/bisect:
* Fix UV2 unwrapping on import, also cleaned up the unwrap cache code.
* Fix saving of RGBA images in EXR format.
* Fixes to the GPU lightmapper:
- Added padding between atlas elements, avoids bleeding.
- Remove old SDF generation code.
- Fix baked attenuation for Omni/Spot lights.
- Fix baking of material properties onto UV2 (wireframe was
wrongly used before).
- Disable statically baked lights for objects that have a
lightmap texture to avoid applying the same light twice.
- Fix lightmap pairing in RendererSceneCull.
- Fix UV2 array generated from `RenderingServer::mesh_surface_get_arrays()`.
- Port autoexposure fix for OIDN from 3.x.
- Save debug textures as EXR when using floating point format.
-Enable the trails and set the length in seconds
-Provide a mesh with a skeleton and a skin
-Or, alternatively use one of the built-in TubeTrailMesh/RibbonTrailMesh
-Works deterministically
-Fixed particle collisions (were broken)
-Not working in 2D yet (that will happen next)
We've been using standard C library functions `memcpy`/`memset` for these since
2016 with 67f65f6639.
There was still the possibility for third-party platform ports to override the
definitions with a custom header, but this doesn't seem useful anymore.
-Used a more consistent set of keywords for the shader
-Remove all harcoded entry points
-Re-wrote the GLSL shader parser, new system is more flexible. Allows any entry point organization.
-Entry point for sky shaders is now sky().
-Entry point for particle shaders is now process().
