Fix occlusion culling for double builds by enforcing float conversion for Embree.

[Rudolph-B]

Fixes #94638

Embree does not support double precision for its geometry buffer. I therefore created a simple float struct to force the conversion from double to float.

[Calinou]

Tested locally, it works as expected.

However, occlusion culling is only functional when you're not too far away from the world origin. I wonder if some form of origin shifting can be used, so that occlusion culling keeps working regardless of where you are.

Single-precision builds still work as usual.

At the origin

Far away from the origin (10 million units)

This is still an improvement over what we have now, so I'd say it's good to merge.

[Rudolph-B]

I removed some old code I missed when switching to the new method

[Rudolph-B]

However, occlusion culling is only functional when you're not too far away from the world origin. I wonder if some form of origin shifting can be used, so that occlusion culling keeps working regardless of where you are.

I don't see any way to implement origin shifting that won't rely on runtime baking, which at least at the moment isn't feasible

[akien-mga]

Makes sense to me.

[clayjohn]

Great work. I like this better than using the marshall function like we discussed in the rendering meeting. It should be lower overhead for doubles builds

[akien-mga]

Thanks!