This allows light sources to be specified in physical light units in addition to the regular energy multiplier. In order to avoid loss of precision at high values, brightness values are premultiplied by an exposure normalization value.
In support of Physical Light Units this PR also renames CameraEffects to CameraAttributes.
Mipmap LOD bias can be useful to improve the appearance of distant
textures without increasing anisotropic filtering (or in situations
where anisotropic filtering is not effective).
`fsr_mipmap_bias` was renamed to `texture_mipmap_bias` accordingly.
The property hint now allows for greater precision as well.
Implement built-in classes Vector4, Vector4i and Projection.
* Two versions of Vector4 (float and integer).
* A Projection class, which is a 4x4 matrix specialized in projection types.
These types have been requested for a long time, but given they were very corner case they were not added before.
Because in Godot 4, reimplementing parts of the rendering engine is now possible, access to these types (heavily used by the rendering code) becomes a necessity.
**Q**: Why Projection and not Matrix4?
**A**: Godot does not use Matrix2, Matrix3, Matrix4x3, etc. naming convention because, within the engine, these types always have a *purpose*. As such, Godot names them: Transform2D, Transform3D or Basis. In this case, this 4x4 matrix is _always_ used as a _Projection_, hence the naming.
`rendering/quality/shadows` is now `rendering/quality/positional_shadow`
to explicitly denote that the settings only affect positional light shadows,
not directional light shadows.
Shadow atlas settings now contain the word "atlas" for easier searching.
Soft shadow quality settings were renamed to contain the word "filter".
This makes the settings appear when searching for "filter" in the
project settings dialog, like in Godot 3.x.
Initial TAA support based on the implementation in Spartan Engine.
Motion vectors are correctly generated for camera and mesh movement, but there is no support for other things like particles or skeleton deformations.
