cloth pinching

[Ge-ZUS]

I'm working on a simple cloth setup, a cloth object (a plane) draping over some dimensional poly letters. The cloth is draping very well over the letters, except that I have these scattered places where the vertices in the cloth are pinching together. It almost looks like the vertices are flipping over, sometimes for a single frame, some much longer.

I've tried a lot of settings with the cloth UV bend, stretch and all that. I've messed with the solver scale some, thickness & thickness force. I've just about gone through most the conceivable adjustments.

Where does this one live?

what about collision offset or resolution? have no maya at hand to try...:sad:

[rartist]

I varied the collision offset, and that really didn't have an affect. The resolution of the cloth object is a little high; I wanted it to drape over the right angles of the letter form well. It actually doesn't really do that. The only thing I have hound that helped is to increase the solver scale. That makes the cloth object behave like a bigger piece of cloth, which is ok. I got it draped over my letter forms well enough to start the next part of the animation where I reverse the gravity to pull the cloth off the letter forms.

What isn't ok is that Maya 7's less than robust cloth engine is crapping out on the solution and giving up. I cranked up the the frame samples from 5 to 12, and that didn't help at all. I'm trying different gravity settings to reduce the shearing on the cloth and take some of the load off the code.

[Frankyboy]

You could try adding more detail to the letters (ie. subdividing the faces).

[rartist]

Right now I'm on my second set of collision objects, and may be throwing those out for a third. I'm having trouble making the letterforms that the cloth solver likes. It seems to have issues with the transitions of the face to the edges. I worked some with the rebound settings, and was able to improve things some. I need to figure out a method to make good letter forms with a good mesh setup.

The beveled poly mesh I have now works better, but the Maya cloth sover keeps getting lost. This is not a complicated setup. Maya's MO for the letters is still based on trim shapes and Cloth doesn't like those. I'm adding a lot to the samples, but it's not helping much at all.

Every time I use Maya cloth, I remind myself why I don't use Maya cloth.

[rartist]

I built a 3rd collision object, I used the type tool in Vue 5 to make a simple poly mesh that Maya likes a lot. I'm still seeing the dimples where the vertices are bunching up. I still have no clue on how to get rid of them. It is looking a lot better, and with the simple mesh from Vue, going a lot faster too.

[Ge-ZUS]

plz be so kind and post your scene for me to have a look at your setup...

[rartist]

I'd love to, but I don't have winzip on this box. I need to look around and see if any of the other stations have it. I have winrar, which knocks it down to about 122k (sans mcc).

I have been able to drape the cloth object over the newest letterforms with some of the dimpling I haven't been able to get rid of. For the animation that I need, I am changing the gravity to pull off the cloth object. I have tried different gravity settings, and frame samples from 5 to 25. So far all of it is too much for 7's cloth solver.

It still doesn't seem to like the right angles of the 3d letterforms, even the latest are by far the cleanest. I really cranked up the gravity and the cloth still seems to hang on the right angle edges. I can see the cloth wrestling unrealistically there. I might try to pull the cloth off with a field, tho that is probably a can-o-worms too; I've never messed with cloth & fields before.

I can't think that there is a way to make the letterforms any more simple without stepping down to unacceptable quality. The Vue 5 type tool made some nice clean meshes. I might need to add some tessellation to the letterforms, but they do look like they are dense enough to do the job.

[rartist]

Fields and cloth with the collision objects is a non starter, it gives up on the first frame. I'm going to go back to using gravity to move the cloth. I might just have to abandon this one.

[rartist]

I tweaked the gravity setting some more, and managed to find something we both liked. I boosted the thickness force, and that seemed to help with cloth piling up around the 90 degree edges of the type. Oddly enough, the cloth solver time went up quite a bit one the cloth was clear of the collision objects and was just hanging in the "air".

[Legolasgleaf]

Fields should work. Just create a radial field, select all the verticies and then constrain to field. Adjust the magnitude to -100 and watch the cloth fly off towards the field. Also if the cloth is stuffing up on certain frames, adjust the verticies and render the frames out. I have found that If the cloth has had the resolution adjusted after it was made then certain parts stuff up, so make the cloth a higher rest to begin with.

Cheers.

[CGTalk Moderation]

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.