Enhancement: Selective block rendering

[ConnorBP]

Use case:

I have structures of defined block types that I want to create renderings of without occlusion by other world blocks.

For this purpose I think it would be convenient if there was some way of selecting which blocks to render on.

One way of achieving this might be an optional "blocktype whitelist", which if set, would have the renderer first check a blocks material for inclusion in this list before continuing the render.

Another option would be to allow an override of the blocks to check against by either passing of a list of blocks with positions or through a callback function to override the hit-check function.

I think having this kind of interface would make for a nice flexible and multi-purpose block rendering tool. This type of direction could even enable some additional optimization if you pass a bounding box where it could quickly check for ray intersection with that box before testing blocks.