maan i was stuck in the vop as well trying to use the attr import node, you saved my bacon 🐖

Note that the polygon has an incorrect shape when you bring it into COPs, i overlooked that when making the video. I believe you have to change your UV Project method to ensure that it has no tiling, e.g. 0 is the minimum bound and 1 is the maximum bound

I realized shortly afterward that there is a different way to do the Convolution Kernel in Vex. You can use Channel Copy to add the mask image as a new plane on the original image. Then use `cinput` and pass the second plane index as an argument.