In godot engine we decide to do a continuous level of detail based a pixel error metric. (simplified explanation pixel-error -> based on fov -> based on floating point error of the meshopt_simplifyWithAttributes function)
The 12 ish lods are automatically generated by https://github.com/zeux/meshoptimizer.
https://docs.godotengine.org/en/stable/tutorials/3d/mesh_lod...
We allow a hierarchical level of detail if people want to set it up.
