* Implements the code to show the boot splash on load using RenderingDevice
* Does not work on X11 when maximized, some platform specific hack will be needed there.
* Fixed and redone the process to obtain render information from a viewport
* Some stats, such as material changes are too difficult to guess on Vulkan, were removed.
* Separated visible and shadow stats, which causes confusion.
* Texture, buffer and general video memory can be queried now.
* Fixed the performance metrics too.
The Optimized shadow depth range was removed in late 2020 in favor
of the Stable shadow depth range, but it still had a (broken) property
that allowed to enable it.
* Colors were imported as 16BPP (half float)
* Far most common use cases only require 8BPP
* If you need higher data precision, use a custom array, which are supported now.
**WARNING**: 3D Scenes imported in 4.0 no longer compatible with this new format. You need to re-import them (erase them from .godot/import)
* Removed entirely from RenderingServer.
* Replaced by ImmediateMesh resource.
* ImmediateMesh replaces ImmediateGeometry, but could use more optimization in the future.
* Sprite3D and AnimatedSprite3D work again, ported from Godot 3.x (though a lot of work was needed to adapt them to Godot 4).
* RootMotionView works again.
* Polygon3D editor works again.
* Ability to allocate empty objects in RID_Owner, so RID_PtrOwner is not needed in most cases.
* Improves cache usage, as objects are now allocated together
* Should improve performance in 2D rendering
* Added a function to ignore subsequent commands if they don't fall within the slice.
* This will be used by the new TileMap to properly provide animated tiles.
* This is the 3D counterpart to #49632
* Implemented a bit different as 3D works using instancing
After merged, both 2D and 3D classes will most likely be renamed in a separate PR to DisplayNotifier2D/3D.
* GIProbe is now VoxelGI
* BakedLightmap is now LightmapGI
As godot adds more ways to provide GI (as an example, SDFGI in 4.0), the different techniques (which have different pros/cons) need to be properly named to avoid confusion.
* Shader compilation is now cached. Subsequent loads take less than a millisecond.
* Improved game, editor and project manager startup time.
* Editor uses .godot/shader_cache to store shaders.
* Game uses user://shader_cache
* Project manager uses $config_dir/shader_cache
* Options to tweak shader caching in project settings.
* Editor path configuration moved from EditorSettings to new class, EditorPaths, so it can be available early on (before shaders are compiled).
* Reworked ShaderCompilerRD to ensure deterministic shader code creation (else shader may change and cache will be invalidated).
* Added shader compression with SMOLV: https://github.com/aras-p/smol-v
