Fix LOD selection in compatibility backend and clean up LOD code

[clayjohn]

Fixes: #67479
Fixes: #89394
Fixes: #78664
Fixes: #73472
Fixes: #78422

1. Applies the fix from Only apply LOD when camera is outside the AABB of mesh in mobile renderer. #92232 to the Compatibility backend
2. Removes camera_plane from the shadow_pass struct (this was unused)
3. Uses Camera transform for shadow LOD calculations so shadows match the object. This significantly reduces shadow acne and stabilizes the shadow profile.

I have another PR coming to fix- #81995, but I separated these changes out in the meantime as these are very safe changes

CC @mrjustaguy

[Calinou]

Uses Camera transform for shadow LOD calculations so shadows match the object. This significantly reduces shadow acne and stabilizes the shadow profile.

It might be worth checking if this fixes shadows in orthographic camera sometimes using very low-detail shadow LODs (despite camera Z far being low), while the mesh is being drawn with its full detail.

[clayjohn]

Uses Camera transform for shadow LOD calculations so shadows match the object. This significantly reduces shadow acne and stabilizes the shadow profile.

It might be worth checking if this fixes shadows in orthographic camera sometimes using very low-detail shadow LODs (despite camera Z far being low), while the mesh is being drawn with its full detail.

Do you have a bug report/MRP for that? I don't think this PR will help in that situation, but I can look into it

[mrjustaguy]

Pancake issue is gone
The Original issue is, mostly gone.
There is still occasionally weird LOD decisions happening with Shadows, but it's really not a big deal unlike the prior two issues that were each in their own ways highly problematic and very obvious even without dedicated attempts to break things like this

MRP:
Test.zip

[Calinou]

Do you have a bug report/MRP for that? I don't think this PR will help in that situation, but I can look into it

You can see it on the last GIF in this issue: #73472

The round object has a square shadow.

[clayjohn]

Do you have a bug report/MRP for that? I don't think this PR will help in that situation, but I can look into it

You can see it on the last GIF in this issue: #73472

The round object has a square shadow.

Thanks! Tested that MRP and I can confirm that this fixes the issue

[akien-mga]

I'm no rendering expert, but the overall code change looks sensible to me, and this would be a welcome bugfix to test in beta1.

[akien-mga]

Thanks!