To answer some of the questions here, the reason this has not been used before is because this technique requires being able to access the quad definitions (ie. which 4 vertices makeup each quad) within the gpu.<p>Up until recently with Mesh Shaders, there's really just been no good way to send this data <i>to</i> the GPU and read back the barycentric coordinates you need in the fragment shader for each pixel.<p>The article offers several options, to support older GPUs, like Geometry Shaders and Tesselation shaders. This is good, but these are really at best Terrible Hacks(tm). Proof of the ability to contort old extensions is not proof of reasonable performance!<p>Notably, geometry shaders are notorious for bad performance, so the fact that they list them as a viable strategy for older devices makes it pretty clear they aren't thinking much about performance, just possible compatibility.<p>Still, I think this is very cool, and now that GPUs are becoming much more of a generic computing device with the ability to execute arbitrary code on random buffers, I think we are nearly at the point of being able to break from the triangle and fix this! We hit this triangulation issue several times on the last project, and it's a real pain.