PDA

View Full Version : The trick to Simulating clothing using SyFlex?


KyleHarrison
11-06-2008, 03:13 PM
Good day everyone,

Im wondering if anyone knows or could point me in the direction of a good tutorial revolving around things like making simulated Jackets, Pants, etc for characters.
All i know is that you should model them separately, what i currently do not understand is how to keep the clothing on the character without stretching way to much. Ive experimented with this before but didn't yield great results.

So now even worse, im looking to simulate a leather jacket, id guess thatd have to be a bit thicker than paper thin, how would i go about doing that?

again any help is appreciated!

greyface
11-07-2008, 01:41 AM
Basically you have:

density: that's the weight of the object, so leather would have a higher density.

stiffness (3 values): these define how the material reacts to forces, leather is much stiffer than silk for instance, so these values should be high too.

you can then select the jacket and the character body and create a 'collide mesh', then set the envelope high enough, that gives it thickness.

To make the jacket stay on the body, use the "pin" constraints. Pin it to say, the shoulders. You can also try using nail, and parenting the null under the torso.

Also, add damping to the jacket, that will soften the animation.

A

adrencg
11-07-2008, 02:44 PM
Basically you have:

density: that's the weight of the object, so leather would have a higher density.

stiffness (3 values): these define how the material reacts to forces, leather is much stiffer than silk for instance, so these values should be high too.

you can then select the jacket and the character body and create a 'collide mesh', then set the envelope high enough, that gives it thickness.

To make the jacket stay on the body, use the "pin" constraints. Pin it to say, the shoulders. You can also try using nail, and parenting the null under the torso.

Also, add damping to the jacket, that will soften the animation.

A

It's easy to say all of that, but you can dial settings forever and you still end up with a piece of rubber. What really is the "secret"?

3dtutorial
11-07-2008, 03:35 PM
It's easy to say all of that, but you can dial settings forever and you still end up with a piece of rubber. What really is the "secret"?


The secret is not to use syflex in the first place. I'm not trying to be a smart ass but honestly trying to get a good result will be quite difficult if not impossible. As you may have noticed trying to dial values into syflex is not easy and you can spend hours, days or even longer trying to find the solution and at the end of the day the time you spend trying to get a simulation to look right could have been better spent using another method. Me, well, I'd avoid using syflex all together... but that's just me.

Good luck.

J

vauric
11-07-2008, 04:13 PM
Well I agree that the values are ridiculous. 0.0001 , etc. hard to use the sliders.
But to say you cant use it, isnt really true.
You have to enter the values numerically, and make very small adjustments.
Look at the values in the syflex help file (theres a tshirt tut), and then play from there.
Dont forget to play with gravity as well as the cloth settings.

Oh, and if you play the simulation, and edit the parameters, you ll see the changes happen in real time, so you'll get an idea of what they do.

You can cache the sim to your hard drive as well, then you can scrub the timeline with the saved calculations.

3dtutorial
11-07-2008, 04:23 PM
Well I agree that the values are ridiculous. 0.0001 , etc. hard to use the sliders.
But to say you cant use it, isnt really true.
You have to enter the values numerically, and make very small adjustments.
Look at the values in the syflex help file (theres a tshirt tut), and then play from there.
Dont forget to play with gravity as well as the cloth settings.

Oh, and if you play the simulation, and edit the parameters, you ll see the changes happen in real time, so you'll get an idea of what they do.

You can cache the sim to your hard drive as well, then you can scrub the timeline with the saved calculations.


In actual fact I never said it could not be used.... I said it in my view there are better ways to go about this. But to each his own! :-)

J

vauric
11-07-2008, 04:29 PM
Sorry, a little misinterpretation on my behalf.

Its very usuable imo, but of course, if you can get nice results in a more manual kinda way, always go the easier route. Thats valid for any simulation really.

As they tend to be less controllable than manual work.

like you said, to each their own. The end result is whats count after all.

3dtutorial
11-07-2008, 04:32 PM
..... The end result is whats count after all.

Quoted for agreement mate!

Cheers,

J

mdee
11-07-2008, 04:36 PM
It's easy to say all of that, but you can dial settings forever and you still end up with a piece of rubber. What really is the "secret"?
Correct units. There is a calculator in the docs, which are located

\Softimage\XSI_6.5\Doc\Syflex\syflex_units.html

Set them right and you are halfway there.

p.s. and I am not kidding, this is THE secret :)

KyleHarrison
11-08-2008, 02:00 AM
Hey guys,

thanks for all the great advice and pointers! itll come in very handy in the coming months!

for now, im going to learn how to make a proper T-Shirt


however, between SyFlex and XSI Cloth, which is technically more recommended for what im looking for? What are the advantages to either or?

Wireframes
11-08-2008, 09:49 AM
There is a calculator in the docs, which are located

\Softimage\XSI_6.5\Doc\Syflex\syflex_units.html

Set them right and you are halfway there.

Wow there is a very good tip, didn't know this :)

Thanks

greyface
11-08-2008, 11:56 PM
Hey guys,

thanks for all the great advice and pointers! itll come in very handy in the coming months!

for now, im going to learn how to make a proper T-Shirt


however, between SyFlex and XSI Cloth, which is technically more recommended for what im looking for? What are the advantages to either or?

Syflex is just much much faster, there isn't any waiting time to recompute the simulation. The syflex forces are also better than the xsi ones. XSI cloth is more integrated though and easier to use.

adrencg
11-09-2008, 01:46 AM
Syflex is just much much faster, there isn't any waiting time to recompute the simulation. The syflex forces are also better than the xsi ones. XSI cloth is more integrated though and easier to use.

I do know that Sylflex collisions(at rest) don't jitter like vanilla XSI cloth. But, on the flip side, it's a pain in the butt to get the settings right.

adrencg
11-09-2008, 02:01 AM
Correct units. There is a calculator in the docs, which are located

\Softimage\XSI_6.5\Doc\Syflex\syflex_units.html

Set them right and you are halfway there.

p.s. and I am not kidding, this is THE secret :)

OMG. You are right! The calculator gets you pretty close. Any tips on figuring out what your object measurements are based on those non-descript grid squares?

greyface
11-09-2008, 04:14 AM
OMG. You are right! The calculator gets you pretty close. Any tips on figuring out what your object measurements are based on those non-descript grid squares?

Just decide on a scale which makes your objects work.

So say if you're making a 2 meter tall character, and he's 10 xsi units tall, then each unit is 2/10 = 0.2 meters.

TheRazorsEdge
11-09-2008, 08:05 AM
The "secret" to getting excellent results with Syflex is indeed the use of proper scale (absolutely imperative) in relation to the model in conjunction with the appendix/calculator which does provide all you need to get started. From there its just tweaking in small increments.

Cheers!

adrencg
11-09-2008, 01:35 PM
The "secret" to getting excellent results with Syflex is indeed the use of proper scale (absolutely imperative) in relation to the model in conjunction with the appendix/calculator which does provide all you need to get started. From there its just tweaking in small increments.

Cheers!

I'd also agree with Vauric, who said entering values numerically is a must.

adrencg
11-09-2008, 01:37 PM
Just decide on a scale which makes your objects work.

So say if you're making a 2 meter tall character, and he's 10 xsi units tall, then each unit is 2/10 = 0.2 meters.

So you're saying all settings are relative to the scale you choose? A grid square can be 1m or 1cm?

greyface
11-10-2008, 12:13 AM
So you're saying all settings are relative to the scale you choose? A grid square can be 1m or 1cm?

exactly.

[filler text]

TheRazorsEdge
11-10-2008, 08:23 AM
Right after scale, object resolution is also an important factor when ie looking at collisions. The higher the resolution of cloth & collider, the better the results. Obviously, you dont have to go extremely high. A smooth or two should do the trick, along with tweaked collision envelope values etc.

Depending on the project, it may also help to build a proxy especially for Syflex, simulate that and then have it drive the original mesh.

Cheers!

adrencg
11-10-2008, 04:47 PM
Right after scale, object resolution is also an important factor when ie looking at collisions. The higher the resolution of cloth & collider, the better the results. Obviously, you dont have to go extremely high. A smooth or two should do the trick, along with tweaked collision envelope values etc.

Depending on the project, it may also help to build a proxy especially for Syflex, simulate that and then have it drive the original mesh.

Cheers!

I think in the docs it says best results are had by keeping the Collide polys .5 the size of the cloth.

adrencg
11-11-2008, 02:40 PM
I've been playing and experimenting with my new knowledge, and I've found some great settings to use for a general, all around cloth. I'm using for hair, but these settings are a good starting point for an object that is around 1/4 of the default grid area.

Density 1 to 4
Stiffness settings:
Stretch 4
Bend 2 (Stretch/2)
Shear 1 (Bend/2)

Damping settings:
.08
.04
.02
(again, subsequent settings are half of the previous)

Global damp: .000002

Gravity -.04

These settings work well for anything that stays well inside the grid, but is not too small.

CGTalk Moderation
11-11-2008, 02:40 PM
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.