Render Culling of LegacyCSL Quirks

[kuroneko]

In some circumstances - particularly noticable when zoomed in - LegacyCSL rendering is culled despite the aircraft being in scene. It superficially looks like the model origin is being used to determine the cullpoint rather than the sphere.

This is particularly noticable with multihead rendering without gap compensation as you can have planes that are visible on one side of the seam, and invisible on the other.