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View Full Version : nCloth constraints without a run-up


adriand
03-27-2008, 01:01 AM
Hey All,

I'm trying to simulate a creature wing using nCloth (kinda like a bat wing). I have low-res, all-quad, meshes that sit between each of the wing-finger joints that act as wrap deformers for denser, skinned geometry (image 1). I want to pin the edges of these meshes to the joints, but I don't want to have to "run-up" the animation from the bind pose. If I move the joints without a run-up, then the simulation resets the component-constraint starting distance and calculates from there (see image 2).

I think I have tried almost every combination of settings on the transform constraints. Is there another, or better way in which I can pin the mesh edges to the joints so they don't deform, but only stretch/compress the cloth?

Thanks,

Adrian

http://lh5.google.com/adriandlm/R-ri4FGS4XI/AAAAAAAAAIA/LxpQ5yoJ7aE/s800/ncloth_constraints.jpg

http://lh6.google.com/adriandlm/R-ri4VGS4YI/AAAAAAAAAII/9dSbxI1Vb4k/s800/ncloth_constraints2.jpg

john_homer
03-28-2008, 11:04 PM
hi Adrian,

what you are asking for is not really possible to have "on-the-fly" with nCloth.

it is very standard to have an nCloth pipeline which includes a runup for the cloth to simulate from bindpose to start pose.

it is possible to do what you want in a round-about way, and I'll describe it, but I wouldn't recommend it ;)

if you duplicate your cloth mesh and bind it to the joints, it will keep any start pose you require relative to the joints. then when you are ready to simulate, just select the cloth mesh and the bound mesh and set initial state from selected. this will move you cloth to the pose of the bound version and update the constraints. you will probably need to refresh the cloth, as nCloth has some update issues.. just hit rewind even though you should already be at the simulation start time.

the problem with this technique, ironically, is that it has no run-up. So your cloth will look like it is "starting". You will have a relax, possibly an interpenetration resolve "bump" etc at the start of you shot... if you are using wrinkle maps you will see them form... the bind will change the edge lengths of the mesh.... problems, problems..

my advise.. try that for fun, then script a bindPose runUp procedure.

.j

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