Geoff Lester

I didn't think it would go in game because although I've done plenty of shader work before, I hadn't in UE4. I didn't think the rendering team would appreciate me messing about with the deferred lighting code (for good reason) :P But they were nice enough to let me :)

You could implement it in materials without doing any shader work, by passing a light angle in to a material via a blueprint, looking up the texture, plugging it into emissive, etc.

Btw: You can find most of the implementation details in Next Generation Character Rendering by Jorge Jimenez and Javier von der Pahlen: http://www.iryoku.com/stare-into-the-future …

Most of the work was finding fun ways of getting all the data I needed from the base pass to the lighting pass, since I needed to align the caustics texture flipbook to the eyeball, and I needed the eye forward vector, etc. Would have taken about a day in a forward renderer :P

(but also, it took me a long time because I didn't know what I was doing, so had a lot of shader code to learn... Thanks for the patience from everyone on the Gears team :))

Popped into my head because I was cleaning up old UE4 projects, and also there was apparently a great talk about the character tech in Last Of Us 2 this week. Which is a stunning game, but I'm avoiding talking about for a while until more of my friends have finished it :)

In the end, the flipbook texture for the caustics was a 4 frame thing that was better to hand paint based off photo ref. I couldn't get much resolution out of it anyway, since I had low precision uvs crammed into whatever was lying around (metallic, roughness probably).