"cape dynamics" almost OK, but collisions problems

#1

That’s fews days from now that I’m trying to “setup” a dress made of 2 part.
To explain the process, at first i focused on the back part of it.
Instead of using SoftBody dynamics (which is too unpredictable IMO), I used :
Bone_Deform+MotionDynamics–>Spring

Here is the setup

The way the dress is moving at this point is ok

And now the problem start, with collisions

-I created a separate objects as the “collision proxy object” and imported it ( a replica of the legs)
-For the Motion Dynamics block
*each Spring have a value for the “Collision Radius”
*there is a MetaEffector for the lower part of the dress, that I selected for the wheight of the Springs
*in the Collision Object tab, I gave the name of the colliding objects
*and i tryied to find the best Motion Dynamics settings to have the best result

At the beginning, the dress “wrap” the leg, collision seems to work.
After animating the legs for a collision test, it’s going crazy…
…
…I tryied to Triple objects or/and proxies with no better result, as adding more poly’s to both…
…and I had abuse of the Shearch tool of the forum…

HELP !
If someone see what to do to improve it, i’m just stuck because of the collision…
Or maybe someone allready did something like this, it will be nice to share, and solve it.

I remember Julez was trying to rig a cape, I don’t know how it turned out.

Unless I find a way, i’ll have to animate the dress bone by bone, that will take forever…

#2

I just tried a sample setup myself and am getting similar results. It’s as if the the object is sticking to the collision object. I reduced the friction to a negative number (i.e. -1) and that seemed to help a bit. But still some wierd popping.

I know you probably don’t want to here this, but I believe most are relying on other apps for cloth effects. LW8’s is pretty darn good and so is C4d 9’s Clothhilde. :frowning:

#3

I got a pretty nice cape rig bt its at work, I was going to make a quick tutorial but I’ve been busy lately, it actually all got started at chikega house…

#4

Thanks for the input Chikega, I’ve LW7.5, and I don’t achieve good result with the MD_controller (like for instance the animation of the collision object is baked, and when I activate Collision for it in MD Property, the MDD file does’nt work: the collision object is’nt animate:shrug:, but the collision effect is working at this point, the cape is wrapping the “stiff” object… ), I heard that LW8 MD was better.

Julez, I checked your cape tutorial before starting the setup of mine, unfortunately, it was labeled comin soon :wink:
Do you think you could E_mail me just the setup ? without the objects if it’s part of your work.
phenobarbidoll_01@hotmail.com

Somehow, I’ll find a way…:banghead: …I’m stubborn.
I tryed a different approach:

3 chains of bones + expressions
Than i animated bones via expressions, in a ruff way, without trying to get the best floating effect (it’s a bit stiff at this point).
After this, I activate SBD, with those settings
Struc 200 1.1 0.5
Shear 200 1.1 0.5
Hold 1 1.1 0.5 (so the deformation does’nt go too far from the bone deformation)

Then the cape animation is smoother, it’s even looking good!, but collision works…when it wants to. Well, collision is the problem again.

#5

I have never been able to get usable collision from Softbodys or Motion Dynamics (it seems to be the same algorithm).
Even in the most simple setup (a chain of bones hanging down and a box to colide against) MDs always fall through the box sooner or later. The bones wiggle around and never come to a rest.

I would prefer “non-realtime but acurate” 100 times over the current “fast but unpredictable” and rather useless collision. :shrug:

#6

I have managed to get “almost” acceptable results with regular softbody and a simple sphere sollision objects.

In your case, I would go for softbody effect on the cape, and colision spheres parented to leg bones. playing with collision radius and other parameters, will probabbly give you better results then motion dynamics bone chains.

Also , dont rely on a realtime preview of simulation. always save out or cache the preview of your scene when dealing with soft or hard dynamics.

but I agree with Thomas,
I wish PMG work out the colision issue;)

g.

#7

…I have never been able to get usable collision from Softbodys or Motion Dynamics…
Humm, i start to figure out me too.

So because of this, after a lot of try I think I find a way that will work for this case (well it have to :twisted:… ) (hopefully it’s suppose to be heavy leather, not silk). I’ll animate it by “hand”, with Bones + Armature .

setup3.jpg753x596

The TOP_ROOT handle control all the bones bellow at the same time,TOP_ROOT2 control just the bones bellow, as for TOP_ROOT3 and finally TOP ROOT4 which control the 2 last bones at the same time.

On the tip of each bone there is a Null used like a pivot point. Then, with the Left or Right handle, i can rotate each Null separately.

This way, i’ll animate the cape, and take care of the collisions by myself. Once the animation work is done, I activate SBD, not for the colision this time, but just to get the cape animation “smoother”. In the SBD tab, I check HOLD with a value of 10 here.
After some test it look ok !

Well, that’s what i found after some days of work, lots of try and mistake…and that what i gonna use.:smiley:
If this approach can help others.

#8

As for me Grzesiekj, I got “almost” acceptable results with a ball against a simple shape, and even with a T-shirt with SBD, i should put this in my resume, ha ha ha ha;)

Well, i tryied softbody effect on the cape, and colision spheres parented to leg bones too, and it was working in a random way, even with playing with parameters and saving the previews in AVI:shrug:

#9

www.flarenova.com/Cape2004.mpj

Here my project file from last year, I was writing a tut but just got busy…feel free to study it.
Its not fantastic but I got some good collision out of it.

#10

Thanks for the file Julez.

But I can’t open it, i guess you have the Studio version, I’m with Animate 4.0e and get this message “ERROR READING FILE. MESSIAH PROJECT LOAD ABORTED…”
:sad:

#11

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.