View Full Version : setting up a strap, best approach?

02 February 2008, 03:41 PM
I want to rig an ammo belt strap like the one in this pic

I tried wire deformer, but since I couldn't rotate the cv:s to rotate the strap, I discarded that idea. I could create a cluster at each section in the strap but I'm unsure of how to set this up in the rig. could i group the clusters and parent constrain the group to the upper body joint. and then create sdk for the clusters so the strap will slack and tighten as he rotates the spine forward and backward?

02 February 2008, 04:01 AM
U can try that but I suggest u go for a secondary animation if the belt is swaying or doin those kind of stuffs..

U can create a simple joint chain and create a spline Ik on it, then add a jiggle deformer to the spline IK curve...N yes tweak the settings..then u can animate the movement of whole body n see the results....

hope that works.....

02 February 2008, 09:37 PM
Also you could do the same thing but with a dynamic curve, used from maya Hair. setup some collision objects and you should be golden. The art of rigging vol 1 talks a lot about this method and a bunch of different ones, so get that book if your really interested.

02 February 2008, 11:48 PM
Thanks alot guys. I actually have those books, but I'm not sure how i should be setting that up. Joint chains seems to offset when adding an ik spline to them. Also I'm not sure if the strap's mesh will intersect the body when he rotates his spine backwards since the joints can't be stretched because if I make them stretchable the dynamic option will not work, or am I wrong here? So I'm figuring whether or not a wire deformer will suffice.

02 February 2008, 03:57 AM
Well, ik spline is a problem but I suggest u check off the auto simplify option in Ik spline handle tool option...Also U can use wire deformer and makimg the vertexes a cluster deformer, if u want to manually control the animation ....

02 February 2008, 04:54 AM
Hi Geuse..!
Use broken heirarchy of bones.. along the strap and skin them and parent to the respective region of the spine..(ie, spin 1, spine 2, chest, etc). hope this would give u more flexiblity in terms of translation, rotation and scaling.


02 February 2008, 07:30 AM
Instead of a dynamic solution, you could have the curve for your spline skinned to joints which are riveted to your body geometry. You'd need the rivet script of course, which you can get on

Just have the joints for the curve point and orient constrained to a particular rivet locator. For more flexibility, you could constrain a controller's group to the rivet, and have the each joint follow its particular controller so you can animate each part of the belt even while it's following the rivet setup, to adjust for penetrations or secondary animation or such.

02 February 2008, 08:25 AM
for how few bullets there are in the ref it will be easiest to use the rivet script to make points in the rig stick on the body. i personally would probably just skin the straps to the same joints as the torso and rivet on the bullets to points on the straps, no extra joints or rigging required really..

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02 February 2008, 08:25 AM
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