View Full Version : I NEED to break the rules of rigging.. need some guidance

11 November 2007, 11:46 PM
Hey guys, I am in the need to make a rig, that needs to strech, needs to have multiple geometry (forarm, bicept, neck, chest, etc) So no skinning. And i need to beable to manipulate it anyway i want, like move the verticies, scale, etc.

So far i made a scelaton and made seperate geometry for each limb(Forarm, hands, leg, feet, etc) and parent constrained the geometry to the bones, and then made some handles and parented the handels to the joints for easier animation.

Then i created new handels, and created SDK's for the limbs so when i pull the handel the geometry will move with it, so like its stretching as if it was skinned.

problem is that i cant move those SDK'd vertices, well i can move them just not animate them, they just snap back into place.

Now i know about clusters i have tried using them, but can't really find a good work around, to beable to stretch geometry, and also beable to move the verts anywhere i want and key them in a animation.

i KNOW this is breaking so many rules for rigging, but this is the kind of workability i need. So any information on any of this or new ideas, please tell me. But also if you tell me, please be specific and descriptive in your response so i can go ahead and give it a shot. Thanks everyone who helps!


11 November 2007, 04:49 PM
DBL Post Sorry

11 November 2007, 04:50 PM
ok since no one is responding, ill post a easier (i hope) question

I have 2 clusters that i am going to TRY and use to stretch the geometry. One Cluster is on the upper leg(Feamer), and the other on the lower leg (Calve), each one is parented to the repectable handle. If i move the lower legs handle, it deforms as i expect,it stretches the leg from the ankle down. But once i move the top handle attached to the feamer, it stretches the leg as i expect, from the knee down, but when i move the top handel, this acts as a influence on the cluster on the lower leg and stretches it aswell.

What i want is to be able to stretch each handel seperate from another, with out one influencing the other. So any help on this? Any answers or ideas would be great@!


12 December 2007, 11:28 AM
having multiple pieces doesnt mean you cant skin. in fact it makes skinning way easier. seriously if at all possible i cut my meshes up before skinning them on any natural seams like if they have clothing. it makes assigning and editing the weights far easier as well as radically increasing the performance by having many simple skinned meshes vs one complex one.

so i would go ahead and skin it and blend shape all your meshes to an unskinned copy for any vertex type tweaks you need to do. you can make your skinned rig scalable and leave the unskinned copy alone.

i do this frequently in character rigs to allow me to just manually animate around rig screwups on an as needed basis by making custom corrective blendshapes in individual shots, for rendered projects. cant do it so much in realtime work alas.

clusters are a huge hassle, especially in rigs that have to scale. not for what you need to do here at all. i do use clusters sometimes, but only on the original non rigged blend shape target, and as a sculpting tool primarily :)

as far as making limbs stretchy, theres a lot of tutorials on that. i personally like to just parent constrain an extra joint that i stick after joint that has the IK effector, this isnt going to give you feature quality, but for mildly cartoony rigs that you want to be able to just overdrive a bit during animations it gets the job done with minimal setup.

as far as rigs that can be moved from either end and stretch infinitely, but without the ends influencing eachother's position- i've had great luck with skeletal chains using parent constraints, with a controller at each end and all the joints in between weighted in different percentages to each controlled to get the desired stretching. the weights can be animated if you need to get really specific. i use this a lot for cartoony spines.

but its hard to understand your situation. some images might help.

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