Cloth Modifier: Making a rope function like a rope...?


#1

Got a character who will be sliding down a rope; for the life of me, I cannot make it function like a rope.
It goes bunches up, it stretches, it goes flying all over the place; I don’t know what I’m doing wrong.

I’ve tried cranking and under-cranking just about every value there is, but nothing works.
I’ve tried making the character’s hand as loose as possible while not letting go, but it still bunches up under his fist.
I’ve tried making everything as slick as possible to make it slide through, but that doesn’t help; increasing the friction doesn’t help, either.
I’ve tried increasing the plasticity, to no avail; it still bunches up and stretches.

How the Hades do I make a rope act like a stinkin’ rope???

Is Cloth just the wrong modifier to use? If so, how do I have a character interact with a rope-like object without doing it all manually? Is the rope just plain too low-poly? Is that it?


#2

Its incredibly time consuming but you can make a rope using first principles. You use the shitty massFX to create a whole load of dynamic-rigid-body objects that are linked together via the ball and socket constraint. Then you create a line and apply a “Spline IK Control” modifier to it. Then the idea is to link the knots/helpers to the dynamic rigid bodies.
The line needs as many smooth/Bezier knots/divisions as there are rigid-bodies that are behaving like bones with physics.
Do a low res test to see if you can achieve a rope like effect and judge whether its worth your time.

MassFX is shitty because it has less functionality than the dated “Reactor” from Havoc it was supposed to replace. Funny how Autodesk doesn’t like paying licence fees every year aint it :wink:


#3

I…have no idea what you just said to me.
Never used dynamic-rigid-body objects.

I guess it’s off to find a tutorial.

You sure there’z no way to tell Cloth to behave itself?


#4

I think, though no doubt someone will correct me, that right-clicking in the empty-space on the main-toolbar (top right) and selecting “MassFX toolbar” would help.


#5

Oh, it’s definitely there. Found it. For sure.

It’s using it that I’ve never done.

Still, thanks.


#6

You can use Cloth or Mcloth, but you don`t use it directly on the rope-mesh.
Instead you create a polygon-strip wth sufficent subdivisions to deform, use the cloth on it for the dynamics and use SkinWrap to attach the rope geometry to the polygon-strip.
Advantages are that the rope geometry doesnt collapse on itself. Cloth thicknes have to be the diameter of the rope. Makes sense?


#7

If, by “polygon-strip”, you mean a plane object, then I think I followed this, yes.
Haven’t used SkinWrap before, but I can probably figure it out from the Help files much easier than I could MassFX.

I’ll try it. Thanks.


#8

I have put together a scene for you to look at. Its saved in 2015 format. Its the earliest version i can save:
https://drive.google.com/open?id=0B7cbctFIhSsgVTF1bXdDTWhKRkU


#9

Well, hopefully 2013 will still open it.

Thank you. :slight_smile:


#10

Alas, no. It won’t load.

Thanks, tho.


#11

Ah, sorry about that. But still the concept is clear, i hope?

Also, if you also wanna follow the MassFX idea of SD3D, then there is this nice tutorial:
https://www.youtube.com/watch?v=ft-czIAPXOQ


#12

Clear…I think so.
Working…not really; for some reason, the plane object and the rope object both disappear at some point during the simulation. No idea why.

Still thanks for the video tutorial; if I cannot make Cloth function, that’ll be helpful. Thanks. :slight_smile:


#13

File saved as 2013


#14

Ah! Bodacious. Thank you! :slight_smile:


#15

I may’ve found the problem

https://www.youtube.com/watch?v=BeTdljJCw4U

It looks as though, instead of sliding through his hand, the rope is getting snagged on it, and stretching above the fist, which probably accounts for how it gets bunched up and flying upward from below it.

But no matter how I set anything, I can’t seem to made it slide through his hand.
I’ve tried making a very loose fist.
I’ve tried making the friction settings really low and silk-like, and on the character, as well (making sure to check the box that uses object dynamics).
I’ve tried setting the rope’s width to really, really tiny to see whether that prevents being snagged.
The character is a collision object, and the only group on the rope attaches it to the building, just for info sake.

D’know what else to try.


#16

Yeah, lookit that:

It’s going straight through the character’s geometry. What do I do about that?


#17
  1. don’t tell me you are using the actual character hand with turbosmooth and all sorts of bells and whistles on it in the cloth sim ?
    (I asked you you not to tell me that !..anyway, I hope you used just a simple ‘cone’ instead)

  2. still, just take the result as is…penetration ? …just stick an Edit Poly on top…animate the verts to however you want
    it to look like…problem solved…


#18
  1. [b]whistles innocently

[/b]02) Well, let’s see whether that cone thing works first.

Thanks.


#19

Is it really neccassary to have this accurate collision for hand->rope? In my file i just used cloth->Group->Node constraint to attach the hand temporarily to the biped hand.
Also i think you need nore segments for the rope to look more convincing.


#20

In my file i just used cloth->Group->Node constraint to attach the hand temporarily to the biped hand

Well, that’s the thing…it’s not supposed to be attached; the rope needs to slide through the character’s hand, like rappelling, like sliding down a fireman’s pole (only it’s a rope, obviously).
This would have been a much simpler endeavor if I’d been going for the rope being held.

Also i think you need nore segments for the rope to look more convincing.

Possibly. But it’s also going to be seen from a fair distance, so it might not matter hugely; I’ll throw myself off that bridge when I come to it.
For now, I’m going to try vusta’s suggestion; it sounds workable (I’d have done it already, except my father came to visit from clear across the country, so…)