View Full Version : It's about the butt!

06 June 2002, 04:32 AM
okay folks, got a question for y'all :D

What kind of boning solutions do you guys use to get realistic bending between the thigh and the hip?

As in where the top of the front of the thigh bends, normally on 3D Figures I see a crease extending way beyond the crotch almost to the hip (or to it) which shouln't be there.

Also, unrealistic bulges on the butt where the skin should contract and wrap around the pelvic bone.

I don't care what software you're using, what do you do to correct stuff like this?

06 June 2002, 05:53 PM
Are you referring to skin slip?

I've only witnessed one application that does this
and its from the folks at
below is a divx with a money shot at the end.

another shot of Skin slip

I'm not sure how this would be done on packages that just support bones and morph-targets without animating patches of vertices on the meshes themselves .
Currently I think ILM and Cgcharacter are the only folks that have a program that does Skin slip.
ILM's is not commercially available though to my knowledge.

Great Question, just wish I could have helped ya with a straight answer :thumbsup:

06 June 2002, 12:01 AM
I've seen the stuff at CGCharacter and I'm quite impressed, but I don't think I'll be using anything like it in the forseable future. BTW, similar things were done for the movie The Mummy using a Maya Plugin.

I don't know which one.

but I'd like to know if anyone has any ideas for solutions using BONES. :D

not necessarily for skin slip, but for keeping the obvious unnatural stuff down.

And perhaps making deformations around the hip that look more natural.

06 June 2002, 10:39 AM
Couldn't you use morphs to achieve the effect you want?

06 June 2002, 11:16 PM
I don't think so, but it might. I think I'd have polygons going off in too many different directions.

I'd rather have the ability to pull skin inward, and I'm thinking a scalable bone shooting back off the hip might work... I'm experimenting.

06 June 2002, 04:09 AM
Unless you are doing some complex muscle deformations or something correct joint placement and skin weights take you a long way.

06 June 2002, 04:15 PM
is there any refference data out there for correctly placing bones in a human figure that you're aware of?

06 June 2002, 09:30 PM
Hey Grey. I don't know of any tutorials for placing bones right off the top of my head, but I'm sure they exist. I know there are some setups in the different forums here that you can download....if they have your software.

But here's a link that has lots of reference for anatomy.

or you could look around yourself on

If I find some tutorials, I'll get them to you. Hope this will get you in the right direction.

06 June 2002, 01:05 AM
you know what would work is a display of bones and colour coded areas on the surface of the model, the coding indicating the weight of the bone on the surface...

That would cross platforms, yes?

Anyway, Rogue, thanks fo rthe links :D

06 June 2002, 07:06 AM
Add a groin bone that goes straight down from the tummy to where the centre of the legs just start to split, Parent this off the spine root.

06 June 2002, 07:41 PM
THAT"s the kind of response I was hoping for!

I'm off to experiment... thank you Dantea :D

06 June 2002, 08:40 PM
I played around with bones pro which has metabones that are supposed to be able to push out the mesh, so theoretically you could place 2 spheres in the butt to keep it from collapsing... only this function didn't work and the mesh would still go nuts.


CGTalk Moderation
01 January 2006, 09:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.