you can do it many ways, here’s a few:
1: you have a pict with alpha and only a particular region has alpha 1
material needs transparency setting to be on. takes more memory, is the most easy
2: you isolate a part of the geometry, the faces you want to use to receive the pict, extract the faces and make a new mesh of it. the rest of the sphere can be discarded
3: you make a pict with alpha with just one pixel transparency around the plain graphic, you rescale uvs to meet the pict ratio, set transparency on, but not repeat(no tiling)
4:you project as a decal using rays and compose, you need to write a shader for this, otherwize you end up doing the same as in case 1.
