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Valter
05-06-2009, 12:13 PM
Hi all.

I have a little animation with character using bones. But the cloth simulation of T-Shirt doesn't follow motion of character.
I have a character with FXColision, a T-Shirt with FX Cloth/FX Collision and a Short with FXcloth/FXCollision. All objects are sub-patched on level 5 and the last for subdivision.

Somebody could help me on it??

Thanks guys

RebelHill
05-06-2009, 12:35 PM
bit old now... but still holds true...

www.rebelhill.net/clothfx.html

Valter
05-06-2009, 01:48 PM
Thanks RebelHill.

I do everything on the site. I tripled all objects, deleted some parts of body of my character and copied FX Cloth settings from site, but now. My short disappear on calculation and I can see only the polygons Fixed in the screen.

Any suggestion???
Thanks

RebelHill
05-06-2009, 01:58 PM
hmmm... checked your collision offset distances and calculation resolution... and made sure that things at "rest" arent closer to each other than the specified distances? When things go crazy like that its usually "pre-penetration" as i call it. I often find it helps to model the clothes a good deal bigger than they shoud be (like rapper baggy)... then use the poly size function in clothfx to shrink them in to fit.

Valter
05-06-2009, 02:03 PM
hmmm... checked your collision offset distances and calculation resolution... and made sure that things at "rest" arent closer to each other than the specified distances? When things go crazy like that its usually "pre-penetration" as i call it. I often find it helps to model the clothes a good deal bigger than they shoud be (like rapper baggy)... then use the poly size function in clothfx to shrink them in to fit.

Yeah.
I'm using 5mm offset and 1mm resolution. My model has 1,50m. None poly is overlap.

Ok I'll try poly size

Thx

RebelHill
05-06-2009, 02:24 PM
ahh... see its not if the polys overlap or not, its if their collision distances do...

if for instance you have 5mm offset on both the collision and cloth object... but at rest the polys, though not intersecting, are only 5mm away from each other... then they are intersecting in so far as the collision detection is concerned..

As you adjust the collision offset, ull see lil red dinks coming out from the vertices of the object, if they're poking through the other objects polys, ull have trouble.

SplineGod
05-06-2009, 04:30 PM
Something else you can try that Ive used many times and works well is to create a collision sphere and parent it to a bone. Size and stretch it to match the characters volume as much as you can. Clone it, move it to another bone, parent it, resize and keep doing this until you have enough of them to cover most or all fo the characters volume. The collisions usually work better and faster.

Valter
05-07-2009, 11:37 AM
Hi all.

Unfortunetly I didn't progress. I have problem with colision yet.

Here are some pics of problem and my setup.
The T-Shirt is parented to Neck Bone and the Short is parented to Pelvis bone. All objects are tripled Polygons. The tripled body is a copy using bones of orginal character (hidden)

73219

73220

73221

Any suggestion???

RebelHill
05-07-2009, 01:03 PM
well first off you dont need tripled polys on your cloth items, just the collision items... second your polycount is ENOURMOUS... the lower res ur objects, the better clothfx will perform, this many polys will make it choke like mental... and lastly, and most importantly... looks to me like your clothing items have actual modelled thickness... no no no... flat objects for cloth calc... then metalink the thickened versions after.

RebelHill
05-07-2009, 01:05 PM
oh, and also... the cloth is TOUCHING the collision at the rest pose there... no no no.

Surrealist.
05-10-2009, 04:33 AM
Good tips there by the way.

I did quite a bit of experimentation and I got good results with these settings and worlflow:

OBJECT TYPE: OBJECT SUBDIV
RADIUS LEVEL: 0
BIND BOUNCE :100
FRICTION POWER: 50
FIX POWER : 50
ROUGHNESS: 0
PROBABILITY 100

And additional settings to cloth object of:
-9.8 gravity on the Y
Collision detection : All
(And I turn all friction and fix settings to 0)

Otherwise all cloth object settings are at the default for the initial cloth Cotton Thick" preset.

Then, to the cloth object a spring value of 6,000 and a Sub Structure value of 6,000. You can do also add Hold structure for more stiffness but not really recomeded. Viscosity and Weight can also be tweaked but are not real key initially.

Work flow wise:

1) Have your initial cloth object highly subdivided in quads. No tris.

2) Separate the shirt and the pants. Do this in two parts. Pants first.

3) Add subdivision surfaces to the cloth object and in layout turn the display subdivision to 0, and set the subdivision order to last. You are not using subD here for the sim. That comes last.

4) Use subdivision surfaces on the collision object so that it is smooth.


Now run the calculation on the pants. (Delete the upper body so that you are not calculating that. Saves much much time.)

Save the MDD file in the file menu of the cloth object. This now overrides the cloth settings.

Add collision to the pants Cloth object. (with same settings as the body)

Add the shirt with the same settings and make the body and pants collision objects. Delete the legs. You don't need these for the calculation.

Save that calculation.

Now to both CLoth objects turn the render subdivision level to 2 or 3 depending on what you get. This will smooth out the artifacts yet preserve the calculation below it in the "stack".

This was the workflow and basic settings for this:

http://www.vimeo.com/2510899

It took a few hours to calculate.

Surrealist.
05-11-2009, 12:27 PM
I can amend the settings a little bit. Here is a screen grab of the cloth settings from what I believe is the scene from that animation.

Other than that I can reiterate what has been said about a thick cloth object. What I did was created a seam.

I hope you can see it from the screen grab. The seam is a ] shape. The result of a multishift on the neck hole edge loop of faces and deleting the inner loop that would connect to the outer faces and then replacing the extruded loop that is moved down from the extrusion. Hope that makes sense. I did the same thing on the lower blouse as well. It stays more or less put with the settings of 6000 on both Sub structure and Spring.

I have found that these settings work well in tandem. That is, the same number. I did little to the other settings, though I found 15 resistance good for the fast motions of the body particularly for the dress.

The last screen grab to show the resolution that was calculated.