This is probably a ridiculously simple question, but I haven't done much (any?) work in creating images in gl (I'm usually creating images outside jitter and playing back in jitter). I'm creating a simple circle (right now using jit.gl.sketch) and controlling scaling, position, and color. What I am trying to add is a blurring/feathering of the border, e.g. much like a radial blur in photoshop. And...I would love to be able to control the amount of blurring...otherwise I'd just create the image in photoshop.
Any pointers? Just not sure what object(s) to use to produce the desired effect.