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jimiclaybrooks
09-08-2017, 12:00 PM
Hi guys, I've been using the cloth engine in LW for a long time now, and I've seen this problem before whenever the cloth was touching the collision object before starting the calcs. This time however, it seems to be exploding when there's no reason for it. When I say "explode", I simply mean, the "move part" of the cloth just disappears. Like BAM!! Its gone!!! So far, I haven't been able to figure this one out. I can include the scene elements if that will help. So far its been almost 2 days and I got nothing, as to whats causing this. So my question is, is the bullet dynamics cloth sim any differrent from the old system? and, can anyone point me in the right direction using the bullet dynamics for cloth instead of the older cloth fx method? I'm hoping that might make a difference. Thanks137863

erikals
09-08-2017, 09:29 PM
ClothFX / Bullet = not the same thing at all

ClothFX has a tendency to "explode" and "jitter" so it is much harder to tame than Bullet.
1- keep real world scale  (a 50cm small man is a no-go)
2- keep resolution to something like 50mm. no higher, unless u know your stuff.
3- cloth should be modeled with a 50mm distance to body. too close will cause problems.
4- for starters, keep collision offset low, yet not too low. 10mm seems alright.
5- trigons give better results
6- a lowres proxy mesh can be useful
7- weighting problematic areas can reduce jitter
8- try not to use SubD / SubP in the first run
9- ClothFX is a wrestle (in many peoples opinion) so lots of tests are needed.
10- you can fix certain areas, however it sometimes comes at the expense of the overall look.

honestly i forgot alot of ClothFX settings, maybe others can chime in...

oh... remembered this >


https://www.youtube.com/watch?v=uBJ50fCRdlU

erikals
09-09-2017, 12:03 AM
first test, had to lower resolution form 50mm to 20mm
at 50mm i got the explosion effect you talked about.
i also got the explosion effect when using a weightmap for the very first "Weight" input


https://www.youtube.com/watch?v=z6k9AQZhw30

so, nothing special at all, however, kinda worked. (attaching file)

erikals
09-09-2017, 12:25 AM
also check >
http://forums.newtek.com/showthread.php?82146-ClothFX-Tests


https://www.youtube.com/watch?v=y-R7MNUrX_Q

Surrealist notes >
http://forums.newtek.com/showthread.php?92820-Cloth-Animation-Tests
http://forums.newtek.com/showthread.php?90999-HardFX-ClothFX/page3

jimiclaybrooks
09-10-2017, 12:02 PM
Wow!! I'm really impressed! I'm sorry its taken this long to respond to you, wifey has been sick and so I've been busy. I must say, in all of the cloth fx scenes that I've done over the years, I don't get those wrinkles in the cloth that are so important. It proves that I've been missing some things. I would ask, could you share that pant leg scene so that I can see the mesh and the setup? I thing that would set me straight as far as all the other cloth sims that I've got to do. and thanks so much for the specs that you've listed here. I've been on point with some of them, but I don't use tris with my clothing, and I don't use such large numbers for the resolution setting, which might explain why I've gotten the results that I have.
Heres a link to some of the work I"ve done so far:
https://www.youtube.com/watch?v=97NGnX4UzbA
Thanks again for your help. Its really gracious of you. take care, we'll talk again soon

jimiclaybrooks
09-10-2017, 12:25 PM
Oh, BTW, am I seeing Caravan in the sun on your youtube channel? If so, we're totally in sync. I"ve been on to that album since it first came out.

erikals
09-10-2017, 05:46 PM
Very nice animation you have there, i would say the cloth in those animations are quite nice. [thumbsup]
oh, no, that's not my ClothFX scene :) the blue jacket arm is made by Dirk
so not my album either :)

little time at the moment, so can't test.

---------------------------------------


Do have a look at Dirk's clothfx settings >


Collision object:

Radius 5mm
Bind/Bounce 100%
Friction 50
Fix 50
Roughness 50%



Cloth object:

Basic Tab:
Weight 2
Spring 9000
Viscosity, Base Value 2, but there is a weightmap in the lower seam, which has a Viscosity Value of 50
Resistance 1 (which, according to the manual, should be much too high..)
Sub Structure, Base Value 500, Weightmap Value (in the seams) 5000
Hold Structure, Base Value 10, Weightmap Value 300

Collision:
Offset 1 mm
Bound 200%
Friction 200%
Fix Force 80%
No self collision (self collision doesn't make much sense on nearly anything a character could wear, imho)

Advanced:
Mode Ratio 50%
Compress Stress 600%
Stretch Limit 5%
Polygon Size 95%

erikals
09-10-2017, 05:52 PM
also check Surrealist. notes >

...one thing I learned about the dress. You don't want friction there.
What happens is the legs pull on the dress and the dress sticks so that it messes up real bad and passes through.
So for the dress 0 friction all around.


Settings for the dress:

Weight2
Spring 6000
Visc 1
Resistance 15-25 something like that
Substructure 6000
Hold Structure 0

10mm collision offset
O on all of the collision inputs (It never seems to make any difference so I leave it at 0)
everything else default

Advanced

Compress 100
Stretch limit 30
Poly Size 100

etc

gravity and
1mm resolution


Collision objects:

Object - Subdiv
Bounce 100
50 friction
50 fix
0 roughness ( could use this if you want not sure what it is good for maybe break up the cloth effect so it is not so smooth)

Except the dress legs had no friction or fix power.

The blouse was the same but 3000 sub and spring so it would appear lighter.

erikals
09-11-2017, 05:24 AM
based on input from Dirk / Surrealist / Dodgy / & Me

these are the Average settings >


Cloth Object:

Basic:
Weight1.5
Spring 5000
Visc 2
Resistance 5
Substructure 3000
Hold Structure 10

Collision:
Offset 5 mm
Bound 150
Friction 150
Fix Force 80
no self collision

Advanced:
Mode Ratio 50
Compress 100
Stretch limit 50
Poly Size 100

etc:
gravity -9.7
5mm resolution
1mm reduces "jittery" effect, calculates slower
40mm calculates fast, however this plausibly cause "explode" bugs


Collision Object:
Object / Object Subdiv
Bounce 110
50 friction
50 fix
15 roughness

Edit1: Nope, that idea didn't work :)
the cloth exploded, even with 5mm resolution. Extremely strange. ClothFX is hard to tame for sure.
Edit2: fixed it by setting the collision offset to 20mm, however using 30mm the cloth explodes again. [agh]
Edit3: using a Lowres collision object (proxy) reduce errors.
Edit4: using baggy cloth (far from object) reduce errors.
Edit5: default cloth settings are actually the optimal. (in general)

subnote: obvious to some, remember that fixing areas reduce errors.
...and perhaps high resistance & hold value.

--------------------------------------------
additional note >
higher amount of polys calculates much slower, however it can look more silk like
https://www.youtube.com/watch?v=mrz2JOenRc8

erikals
09-11-2017, 01:33 PM
last test... (hopefully)


https://www.youtube.com/watch?v=Qp9rqleHC14

scene file >

jimiclaybrooks
09-12-2017, 07:20 AM
dude, I can see that you spent a good deal of time putting all of this together for me. A thousand thanks, I do appreciate it. I'm happy to say, I did get the cloth robe working, and in no part thanks to your input. Some of these numbers are unimaginable to me. 6000 for stress compress??? Wow!!!
Looks like I'll be spending some time experimenting with the cloth engine a whole lot more. Amazingly, I really haven't been using weight maps with my cloth sims, so that's a whole area that I'll need to get up to speed on. I agree that fixed areas on the cloth sim can really spoil the effect, but that is what I"ve had to do at times just to get something reasonable. Thanks for the compliment, coming from you it really means something. As I said, I have spent alot of time doing cloth, but admittedly, I'm always in a hurry to crank out stuff, and sometimes the quality of the work has suffered... so I'm really trying to change that. If you put something out there, you can't bring it back in, so it needs to be as tight as you can make it. And this will really help me in that regard. Take care, and thanks again.

jimiclaybrooks
09-12-2017, 07:47 AM
Got a question for you. I saw a video that said, bullet dynamics could calculate cloth better than the older cloth engine could, and it shows several layers of material falling on top of each other at the same time. Am I to understand that bullet dynamics really doesn't work with cloth sims for characters? and if so, why would they say that it does? I thought the skirt animation that I saw was done with bullet dynamics?

erikals
09-12-2017, 08:00 AM
hi, happy to help out  :)

in a subnote on my Youtube channel i mention that for stuff like this, (jackets / jumpers) Bullet is probably the way to go.

Bullet has less jitter, is fairly stable, calculates faster.
- a slight minus is that it doesn't appear "Silky"
- also it does not have complex wind features like ClothFX.

unfortunately i haven't had the chance to test Bullet much, hope to do this later on.
there is also the $200 Syflex plugin, that i also need to test further.

so ClothFX for jackets/jumpers/tight cloth, is doable, however i wouldn't recommend it if the animation is long or the project needs to be done in 1-2-3.
i wouldn't go for more than 20+ seconds animation in that case, since you are bound to get errors every now and then.

erikals
09-12-2017, 02:46 PM
did some Bullet Jacket /Jumper tests, seems to be very few example available.
first test, so not optimal, however i think this is pretty close to as good as it can get for a Jacket / Jumper.


https://www.youtube.com/watch?v=KxyUvz_84Yg

erikals
09-12-2017, 02:50 PM
some additional notes...


https://www.youtube.com/watch?v=14qMfJG6Ajg

jimiclaybrooks
09-13-2017, 10:45 AM
Wow, things have changed. Last time I checked into it, Syflex was a thousand dollars! Now it $200? That's not bad. Its a shame that the fire and smoke plugin isn't that cheap as well. Anyway, thanks for the testing with bullet dynamics. I understand that you can't edit the fabric like you can in cloth fx after the calculation, is that correct? If that so, it is a major drawback. Also, not having wind and collision fx with the cloth is also a bummer, but I guess that's just the way the cloth folds huh? So thanks again fo

erikals
09-13-2017, 10:55 AM
but I guess that's just the way the cloth folds huh?

LoL, yes! :)

did run some Syflex test today, however i find that it doesn't provide good results for Jackets / Jumpers. i'd advice to stick to Bullet for that.

yep, only ClothFX can be edited afterwords.

however, i believe there are ways to add softfx with settings set to Zero, to deform any type of simulation.

tricky stuff... :l

Julez4001
09-17-2017, 02:49 PM
Wow, things have changed. Last time I checked into it, Syflex was a thousand dollars! Now it $200? That's not bad. Its a shame that the fire and smoke plugin isn't that cheap as well. Anyway, thanks for the testing with bullet dynamics. I understand that you can't edit the fabric like you can in cloth fx after the calculation, is that correct? If that so, it is a major drawback. Also, not having wind and collision fx with the cloth is also a bummer, but I guess that's just the way the cloth folds huh? So thanks again fo

Jim,
I just watch your videos. Is that for your church or your day job.
You have a lot of wonderful cloth dynamics going on. Can you please share your tips to get that much crunk out? Look at the volume of shots, superb job.
If you need help in your tabernacle videos, let me know..I would love to help you on your subject matter. With any thing, a second pair of eyes and different experience background can help out.

PM me or facebook "Julian Herring"

erikals
09-17-2017, 09:53 PM
did run some Syflex test today, however i find that it doesn't provide good results for Jackets / Jumpers. i'd advice to stick to Bullet for that.

update; got good results from Syflex in a later test, the trick was to Uprez the cloth object to avoid jitter.

jimiclaybrooks
09-17-2017, 10:24 PM
Julez,
Thanks for that. The video was for my church and for the rest of the world too. Unfortunately, since my business when down the toilet, its not my day job anymore. It was when I started, but that was a long time ago. The recession put me out of the art business, so I only work on the project part time these days. Lots of stuff going on right now, and of course I appreciate your appreciation. I do need some help, cause I've done all of it so far by my lonesome. So I would be glad to have someone I could bounce some things off of. I'm sorry that I can't pay you since my wife's been sick, and I'm just not in a position to do so just now. Thats why I'm goin solo. But I'll be happy to share what I have with you, (which is worth more than money anyway, as far as I'm concerned)
erikals,
My thanks to you to for your help with my cloth work. By hook or crook I'm gonna get syflex, tho it may take awhile. Its such a powerful tool. Can't beat the price. For now I"m gonna have to content myself with cloth-fx and bullet dynamics, which aint bad.

erikals
09-17-2017, 10:56 PM
happy to help out Jim :)

hopefully Syflex will be just what we need.
further tests are needed on this corner of the world, it does look promising though.

if you choose to buy it, make sure to check this intro video >
https://www.youtube.com/watch?v=kwpYYwReF5o

best of health to your wife, and best wishes.

jimiclaybrooks
09-18-2017, 04:49 AM
Oh yeah, saw that. Its one of the reasons why I want Syflex. And thanks for your best wishes to my wife. She had cancer, and it was a close call for a while, ... I almost lost her, but her cancer is almost gone now thanks to the Cancer Treatment Center in GA. That place is awesome!!! We're not out of the woods just yet, but we're really close to the finish line now. I appreciate the well wishes. I know she does.

erikals
09-18-2017, 04:59 AM
hopefully in the future cancer will be a thing of the past. modern medicine saved me twice from "simple" problems.

we are lucky to live in 2017, even with the challenges it brings.