Difficulty Rigging a Hip/Groin Joint

BlazeCell

I have a simple stick-man model which I'm trying rig up. I've got most of the joints bending in an acceptable manner, but I can't seem to get the hip joints to bend properly.


Here's an image of the rigging issue where the foot is raised a bit and nothing else:



Here's the same pose with bones visible:



Here's the default pose:



Here's the default pose with bones visible:



And finally here's the base mesh in edit mode before the subsurface modifier is applied:



The full album of screenshots is here if for whatever reason the above images stop showing up:
http://imgur.com/a/p8Itb/all


Does anyone have any idea on how I might resolve this issue with the hip bend?

monster

Part of the problem is your topology, and part is vertex weighting. I know you want a simple character, but unless you want to segment him, the rig isn't going to be so easy. You should consider adding some helper joints or morph targets that automatically correct the mesh as you bend and twist the joints.

Here is a good reference site for topology: http://www.hippydrome.com/LLeg.html

punchface

That hippydrome link is nice, monster. Thank you!

pf

BlazeCell

Thanks for the reply Monster.

You were right, it was mostly a topology issue with some weight adjustments needed as well.

I mainly just needed to add some additional loops around the pelvis-leg connections.

JustColorado

From the pic that you posted it looks to me like
you enough topology to make that area work. I have seen nice
results with a lot less topology, and good weighting.


It looks like you have 100% weighted vertexes at
areas that need blending
Play with the weighting more
I like to have one edge loop at 60/40, then 70/30, 80/20, 90/10, 95/5 then 100
and then I do the opposite weighting on the other side.
But there is no magic number. you just got to play with it until it looks right.
and that area is definitely one of the hardest.

BlazeCell

Thanks for the input JustColorado.

You're right, I was doing 100% weighted vertices. Better weighting likely could have made things better, but I opted for creating clear deformation areas.


New base mesh:



New hip bend:



New hip bend with bones visible:



New imgur album here:
http://imgur.com/a/P2EUm/all


I did add some 50% weights to topmost ring of the upper legs to get a bit less mesh intersection, but the problem was primarily solved with triple crease loops.