colortwist

Advanced character rig (7/???)

Added 2019-02-10 08:59:12 +0000 UTC

Work continues on the facial rig.

A little while ago, I noticed that the intersection between the corneas and the eyelids was getting pretty bad. Normally this is something you can just ignore because the eyelids should be thick enough that the cornea won't actually intersect through them, but if the cornea is realistically shaped then there's a good chance the bump on the front of it might actually be too big to hide behind an eyelid of realistic thickness.

Prior to this system, I was kinda cheating and actually flattening the corneas as they neared the edge of the eyelids so they'd sort of slip underneath them- hopefully without anyone actually noticing. This seemed to work well enough, but I wasn't a fan of this system since altering the geometry of the cornea means you're messing with the reflection on the front of the eye- which tends to look really strange under animation, since you'll actually be able to see the front of the eye inflating and deflating as it moves around in relationship to the eyelids.

So, I landed up ditching that and implementing a displacement based system instead. Now the eyeball geometry remains fairly consistent (as it should) while the eyelids actually warp over and around the cornea bulge, thus maintaining a fairly realistic result. It's a pretty subtle effect, but it does actually influence the way the eyelids render out- especially when they're partially closed or clamped shut (something I'm sure I'll be dealing with a lot in the future). As a weird bonus effect, it's now possible to see a character's eyes moving around from underneath the eyelids when the eyes are fully shut.