Another XSI Cloth Problem

[hobophobik]

I've looked at other posts in this forums concerning cloth, and there all several years old or don't really answer the question.

Does anyone have any tips on making an item of clothing out of XSI cloth. I am tring to make a shirt, it is modelled using a polygon mesh, and i have set appropriate cloth settings to allow in to rest on the body of my character without ripping or going through the mesh. This was achieved with a combination of thePushlength, friction, gravity, and tolerence settings.

The main problem comes when the character is animated, the shirt ripps itself appart, and deforms iraticly. I was thinking i might be able to prevent this by constraining elements of the shirt to the characters mesh. I tried using centered clusters on the neck and sleeves, which were position constrained to corrosponding centered clusters on the character mesh. But no success

I'd love to know if anyone has successfully made an item of clothing in this fashion, as i'm beginning to believe that the cloth features of XSI are limited to simulating things such as curtains and pirate flags. The lack of tutorials on this subject also points to it being impossible.

If i succeed with this, i vow to write a tutorial to help all other confused XSI cloth users.

any help welcome, cheers, hobo

[adam_stewart]

QUOTE
I was thinking i might be able to prevent this by constraining elements of the shirt to the characters mesh.

With some points tagged, create a local cloth cluster from the simulate-->cloth toolbar. Check the "nail" parameter on. This keeps that part of the geo rigid in the cloth simulation. This cluster can be influenced by envelopes (or other deformers) the same as the rest of your character, so you can use this to in essence constrain the local cloth to the underlying skeleton. You may have to play around with the order of the construction history to get it to work. I believe the cloth operator should be above the envelope but it could be the other way around.

A couple of hints:
- you can use a lower res geo proxy with cloth simulation as a cage deformer on the high res geo. Then you can plot the shape of the hi-res geo before you render for a quick and tidy solution to some common problems. ()

• instead of using your character's actual geometry as a collision obstacle, use primitives to approximate the body parts and make them children of the skeleton. Saves you from having to check the "animatable deformation" box which can slow things down a bit. I always keep double face collision on. The other advantage of this is that you have a localised control for the position, scale, and rotation of each of your collision objects, so you can easily tweak problems on a shot by shot basis through the collision simulations. You can also shape animate the collision objects in problem areas. Don't be afraid to use the "animatable deformation" if you need to. It does increase simulation time a bit, but it is sometimes the easiest solution.

  • if you have multiple cloth objects and you need them to interact, the best way is to simulate one piece of cloth, plot its shape, then simulate the other piece with the shape animated geo as an obstacle (actual shape of course).

[schmauli]

well it might be a bit late but for anybody that stumbles upon this then.

I had some tries at a 3d tshirt myself lately and it gave me a headache big time. But i got some results eventually. What i found that works is that you shout realy increase the iterations per frame on your collision, this is default set to 1 i believe. That is way to low. Just start by increasing it to 10 and pherhaps even more.

What i thing happens is this. When things move the collission of some points will be between frames. This means some points of your cloth collide and bounce and some don't and keep on going. Thus the 'ripping appart of the shirt'

It is not nescesary (difficult word) to attach or constrian the cloth to your character to have him keep his clothes on. Provided they are not too big.

Another parameter that can easily make the cloth animation fail is a too low stretch limit. However, keeping this as low as possible will make your clothes look nicer.

Further more you should always avoid interpenetration of your obstacles. if your cloth gets caught between the penetrating surfaces the animation is a goner.

hope this helps anybody
Paul

[deadrabbit]

Make full use of the Syflex Plugin, It is awesome for cloth.
Make sure you use the units correctly for scale and adjust the envelope and you will have no problems!

For beginners - check out the Digital Tutors 'Syflex for MAYA' tutorials - most of it can be applied to XSI!

D.