I'm trying to project a caustics texture from a light in Cycles. It works with Point or Spot lights, but I'm trying to emulate the sun projecting caustics underwater, so I need the shadows and light rays to be parallel. Here is an image from the test scene, note that the shadows are not parallel.
And here's the light's material setup:
The question is if there's a way to project from a Sun light. I know that an option is to take the light far, far away (that's why the Light Falloff Node is there, for controlling the strength).