I couldn't find in Apple documentation whether or not RealityKit supports LOD.
In games engines, LOD is being determined at runtime according to the position of the camera relative to the model. If the camera is far, a low-resolution texture would apply to the model. If the camera is close a high-resolution texture would be applied so that the user would be able to view even the smallest details.
The answer is: Yes, it partially does.
According to RealityKit's official documentation:
RealityKit helps you get the most out of textures. For example, the framework automatically generates and uses
mipmaps, which are a series of progressively lower resolution variants of your texture that improve render times when applied to distant objects.
However, at the moment there's no any API tool (whether using Swift for RealityKit or Python for USD Schemas) allowing you make less detailed versions of your models (with lower number of polygons) that are viewed when they're further away from the camera.
