This feels like computer graphics and the 'screen space' techniques that got introduced in the Xbox 360 generation - reflection, shadows etc. all suffered from the inability to work with off screen information and gave wildly bad answers once off screen info was required.

The solution was simple - just maintain the information in world space, and sample for that. But simple does not mean cheap, and it led to a ton of redundant (as in invisible in the final image) having to be kept track of.