Affected nodes:
- DirectionalLight3D, OmniLight3D, SpotLight3D
- ReflectionProbe
- LightmapGI
- VoxelGI
- GPUParticles3D (but not collision/attractor nodes)
- AudioStreamPlayer3D
This reduces visual clutter in the editor with 3D scenes.
The lack of icon gizmo made it no longer possible to select Camera3D
nodes in the 3D viewport by clicking on them.
A new Camera3D icon gizmo was designed to be direction-neutral.
This avoids the issue that the previous icon gizmo had, since it was
always facing right.
This also adds icons for CameraAttributesPractical and CameraAttributesPhysical.
