Building on @xordev.com's tutorial on glows — here's a shader I wrote using a Lorentzian function for brightness falloff. Its closed-form antiderivative makes analytic motion blur straightforward: fragcoord.xyz/s/lmojqltl. I've made it public domain, enjoy!

If you are interested in learning shader development, this tool helps a ton! Being able to see the individual pieces is a game changer. Thank you @xordev.com