Soft Cloth Question

[lovefailer]

Hi there,

I am new to cloth and having some questions would like to ask the experts

I have to simulate the cloths of a cleaner which incl: short dress with torns and tear at bottom (model torns), a white drape on top, white shirt and sleeve (sleeve modeled separately) which has those soft budge up (those near the shoulder which u normal see at the fairy princess dress).

For the inner dress, I tweaked from the preset maya silk presets, and top-constraint to the body (col surface). The drape is from shirt preset. Shirt from shirt preset and sleeve from shirt preset.

However, I encounter some prob:

1. Around the point->surface counstraint, the cloth offten bunch up unexpectedly
2. The drape bubble ard a lot during sim. I've set body, dress and drape collision layer to 0,1,2 respectly but still doesn't work
3. I wish to hav the torn part to be very soft and easily to be influneced by character motion and generate those thick wrinker that usually see. However, it's only stiff and springy. I've tried painted mass, stretch (very low at the torn part) but it doesn't help. What I am looking at is those dress with dress which pretty firm with big wrinkle at top and towards the end to hav more those flapping and soft material that easily move and pushed with even little char motion. I've read the help but havn't figured out which paramaters control such behaviors
4. The animation is short like a dance with many twist around ... I tried to achieve sometime like the balerina dancer demo for nCloth but can't get the twisted effect (which the bottom of the dress always lag behind, then follow up and even over shoot then flag back till settle). I guess the top should be silk like (low mass, more stretch, low friction) and have tried painted those but it's not right ...
5. In the twist, at certain frames the dress has interpenatration. I've up selfColIter = 32, substep n col = 32 with all the suggested from maya help but to no avail (though the simulation is pretty much slower)

Any light or suggestion to the above would really appreciated ...

Thanks in advance

[chris-wombold]

I'm not sure if I can answer all your questions as I'll a little more information.

1. Constraints can cause to bunch up if they are too strong. This means that your constraints are fighting collisions, and in-fact since your whole sim seems to be failing this is probably just a side effect of that.

2. It's best to make the sim as simple as possible. Don't simulate all your cloth at once; this is only asking for trouble. A very common mistake is to do too much at once. You may think that you've got all your settings correct, but the more you try to do at once the more potential problems you will have. This means if one thing goes wrong you have no idea where to start looking for that one thing. If you break down your process into smaller chunks, it's easy to spot problems. With a multi-layered cloth character here's what I do: I only work with one piece of cloth at a time, starting with the inside working out. Once I have the inner piece simulated, I cache it and work on the next one. This way I keep my simulation simple and my outside cloth will collide with my cached cloth just like a collision layer without the complication of multiple nCloth simulations.

3. Take a look at your Scale Attributes, the default for nCloth is meters. This means that ever grid box is calculated as one meter. You need to make sure you Scale matches you character. If the scale is too big the effects of gravity are reduced and your cloth will look stiff. Your cloth may also be stiff because it has insufficient geometry, if you want more wrinkles in a certain spot then add more spans there.

4. It sounds like this is caused simply by the rest of simulation breaking. Remember KISS. (keep it simple, stupid)

5. If an nCloth fails somewhere it doesn't recover. So your dress most likely is failing elsewhere and you may not be noticing it. Following the above steps may solve this problem. If your still having problems increase the self-collision distance.

Hope this helps.