Is this hip topology workable?

Zablorg

Hey all,

Just looking for some quick feedback before I progress with this character- I know that joint deformation issues are to some degree inevitable and can addressed with blend shapes, so without incorporating those I'm not sure how off-base I am.

I'm basically just testing how well my character is responding to leg motion:



This first pass certainly doesn't look great, and I'm basically wondering if this can reasonably be countered with more thorough weighting and blends.

As you can see I've set it up so that the edges flow up the pubis around the hips, per convention. And if nothing else it seems the creases I'm getting are more or less in line with what you'd expect of the groin. It could probably use more loops around the groin, but honestly I see similar stretching issues even with that.

I've seen topology where the edges that trace the hip go under the leg and up the buttocks, and I've tried it- it's been tricky getting that to work correctly with the butt however, because it seems to inevitably cleave it into two perfectly defined buttocks instead of the bepantsed situation I'm trying for.

Zablorg

In case anyone is interested, while researching further on this I found an interesting hip rigging tutorial, which makes use of a number of extraneous bones around the pelvis to better control automatic weight-generation and deformation volume. I aim to implement it and see if that has much impact- though the difference seems to be more subtle than just the effect on leg-raises.

RN

There's a different technique that involves using a "pose reader mechanism". It's described in here for Blender: https://blender.stackexchange.com/questions/112657/how-to-drive-shape-keys-based-on-the-angle-between-two-bones/112658#112658

There's Maya plugin that did this for quite some time.

You set up a reference bone that points in a certain direction -- the direction you want the corrective blendshape to be at its peak.

The more the bone you care about --like the thigh bone-- points in that same direction, the more the blendshape is pronounced.

You set up as many pose-reader bones as the correctives you need (it's a 1 : 1 relation).

Hippydrome suggests 4 correctives per limb on a humanoid character: up, down, front and back (he calls them "UD" for up-down and "FB" for front-back. "Tw" means twist, or upper arm roll, which is another doozy to get without flipping).

For arms in A-pose you might be able to get away without having to sculpt their corrective 'down' pose (seeing as the resting arms are close to that position already).