if i have lots of wires that have a chance of penetrating each other how would i stop that?

i think one solution would be to use a wire deformer and have it deform to lots of rigid bodies controlling control verticies... i think thats what they did in UP for the baloon strings

but can anyone suggest other ways?

hair follicles with self collisions on? the question would be is it really a big deal if they interpenetrate. Do you see it. What is it for?

Worzel: yeah sure, here's an attached picture of part of the setup (i was wanting to know how to do it before i actually modelled all the wires so not all of them are here, but you should get a fair idea of where i'm going with it)
the model is a robot (transforming alarm clock specifically but that's irrelevant) the wires go from the chest to the hips and around the model's spine. and the wires may or may not interpenetrate each other if they were just bound to an ikspline, but i'm guessing they would if there are lots of them


neuromancer: not sure what you mean about hair follicles.. i'm not familiar with hair at this moment.
i'm not sure if hair would be a decent solution, the wires are somewhat fatter than hair and they are pretty visible

Are you looking for a dynamic effect with each wire moving independently of each other?
1. You could try using nCloth.. Constrain several rows of verts at the top and bottom and paint off the influence of the constraints for
each cable. Turn collisions on.

2. With the dynamic hairSystem, you'll be able to set an offset attribute for the collisions (hence making them thicker than regular hair strands)
I've not had much success with collisions using maya's hairSystem myself... They seem pretty erratic, even when you crank up the over sampling.

Personally I'd rig a deformer set up and not worry about the dynamics.. too much of a head ache!

Collision detection can be pretty CPU heavy. Unless you're really wanting to see those wires pull against each other, are you sure you're going to animate the model enough that they end up rubbing? Could you do with shape / bevel along a curve?

The only problem with ncloth is that it has to be the unlimited version which is kinda expensive. But if you have the luxury to use unlimited then ncloth will definintely be my first choice.

I would probably make IK chains for the wires and set them as ncloth object, then just like Andy said paint the input weight on the top and bottom to 1 and paint the middle bit to whatever value u desire, that way u get nice collision/secondary animation in the middle and stiff on each end.


Ncloth simulation is actually pretty fast once optimized, especially when dealing with light geometry. Perfecting it does take a bit of investment in time however


Seriously though, best to just stick to the basics and just using ikspline, pretty much will get you 90% there.
It could actually be the fastest way - just using clusters on splines to get them out of the way when it happens.

andy: thanks for the input, i'll look more into ncloth, i'm slightly scared of maya hair given all the horror stories you hear about it! but someday i'll see it for myself and probably wonder why everyone had a problem with it or wonder how such abomination could ever exist

lancer: yeah, i'm aware of simulations being heavy on the cpu, and even though the wires will be somewhat obscured but still clearly visible i didn't want it to look like they were going through each other.
hmm... not sure what's worse, trying to hand animate many wires and probably limiting the articulation of the robot's body which would take forever or letting someone else do the work (ie the simulation) and letting that take up all the time. both solutions sound time consuming to me
i imagine they would rub up against each other and the spine of the robot when it starts moving twisting its body
i'm not sure what you mean by your suggestion of a shape/bevel along a curve, can you please explain?

shortndeadly: you're right, ncloth is only in unlimited, but in 2010 it's just there.. i suppose since xsi has everything in both it's equivalent to unlimited and complete versions such move would make sense.
my current solution is to use springs and hinges on rigid bodies that parent contrain clusters along a curve which has a surface or polygon extruded along it with the extrusion history still there.
although i'm not so sure that such solution is without its short comings
also, i had the impression that cloth didn't need any sort of IK on it. i've played with cloth once before (or more of just watching a plane-turn-nMesh fall onto a cube) and i thought i was just going to turn those cables into an nMesh and it would just work.
i'll be looking at how ncloth works later once i can start working on this again but i am wondering how IK has a place in nCloth

Sorry - I meant extrude along the curve, where you start with a nurbs circle and make it follow a path to form a wire. I think you may already be doing that though I was thrown off because it wasn't heavily smoothed and I mistook the current wires for poly.

Oh the other thing with nCloth is, you could rig each cable with a deformer or skinCluster set up, and then use that inputMesh to guide your simulation.
Again you can paint the influence the inputMesh has.. so at the top and bottom it would be high, and in the middle it would be low.
Similar setup to a trouser leg incidentally!

cool - good luck!

lancer: yeah, those wires you see now are just extrusions without deleted history so they can still be influenced by the curved used to make them.
i wonder how you would rig it though

andy: thanks, i'll keep that in mind when i do some experiments

It depends whether you really want automation of the "not going through" stuff. If it's for rendered output like a movie, you can minimise the number of points in the wire CV curve to make them manageable (wire doesn't really bend that much anyway if it's not too long and dangling... try to have not much more than start / stop and middle for a wire), hook those onto manual controllers and set up a "wirecam" for checking collisions on a final pass of your animation... it's kind of annoying to keep checking but as long as you're not making something epic long then it may not be so bad to correct just the frames where they go bad. You'd have to make sure it doesn't end up looking like the wires were mysteriously jumping out of each other's way (keep them touching where they were going through).

Alternatively splines, ncloth and what others have been saying may make it easier in the long run. Think you might need to run a few experimental tests to actually see which is going to work best.

You could also render the wire and then re render the external wires so that the interpenetration is not seen.