It's been awhile since I've looked at the code, but take a look at the code around this https://github.com/amoffat/metabrite-receipt-tests/blob/master/blender/r

It's been awhile since I've looked at the code, but take a look at the code around this https://github.com/amoffat/metabrite-receipt-tests/blob/master/blender/receipts.py#L269-L285 https://github.com/amoffat/metabrite-receipt-tests/blob/mast... for mapping from UV space to image space TLDR: using a KD-tree, I find the face containing the UV coordinate. Then I transform the UV coordinate to barycentric coordinates within that containing face, then put that barycentric coordinate through the local -> world -> view -> perspective transform matrices