Help me find out what this texture mapping technique is called
What you see in the image called a UV map. That is, it is simply texture coordinates to be looked up encoded in a image. Same thing happens in all texture lookup in 3D there is a underlying sampler that picks where to pick texture color from.



Image 1: Image showing UV map of two overlapped triangles and sampled texture with same UV coords

Here are the sources for those images, please do not overwrite the sources.


Demo showing the UV map
Demo showing the texture