This texture was generated in Filter Forge, a Photoshop plugin that allows you to create your own filters.
The ultimate Proportional Gradient.
Most of the work is Uberzev's, who had come up with a faster method to accomplish this feature. I added the automatic detection of horizontal/vert
The last couple of steps demonstrate an easy way to add controls to the Proportional Gradient by mapping it to an elevation gradient. The main output of the snippet is really just the vertical and horizontal proportional gradients without the last two steps of adding controls to them.
gradient, proportional, non-square, automatic, snippet