making cable faling - how to avoid the cable intersect it self?

# 1 23-09-2005 , 12:52 PM

Registered User
Join Date: Sep 2005

Posts: 21

making cable faling - how to avoid the cable intersect it self?

I'm making an elevator cable snap and falling down the shaft.
Now, I extruded a circle curve (cable body) along a straigt curve (cable path), while having construction history on.

I created clusters along the straight curves vetices.
I created little cubes an placed them on exact the same vertices for the straight curve.
I point constrainted the clusters and cubes (one by one).
I spring constrainted the cubes. Again one by one. 1 to 2. 2 to 3. 3 to 4 and so on.

This gives me a row of cubes interconected with springs and each cube again controling the shape of the straight curve.
Which again controls the shape of the extruded circle (the elevator cable).

Now when i translate a cube, it alle works fine the cable start to swing and ocillate.

I now want the cable to fall down. I atach graviti to all the cubes and the fall pulling the curve with them.
It works fine. But on the way down the curve spins around and intersect it self. This doesen't look good. The cable would
have been made out of steel and can not pass throug it self.

I tried to make the extruded circle a passive rigid body, but the deformation of the straight curve (conected to the extruded circle via the construction history) seems to overide the passive ridgid bodys function of not passing through it self.

Have I taken a wrong aproach in order to make the cable?
Any ideas?

Quote

# 2 26-09-2005 , 05:11 PM

Subscriber
Join Date: Feb 2005

Location: Winter Park, FL

Posts: 62

Well first of all right after you create everything and its ready to be made into something dynamic.. delete history, all that modelling information isn't necessary...especially when you're dealing in dynamics and that can make a world of difference

secondly, I would use maya hair for this kind of feature, make the curves where you want the cable to be and end them where you want them to snap... then select both curves, and under the hair menu make them dynamic, then go into component mode, select the points that meet on the two curves and make a hair to hair constraint and key frame the glue attribute...

play around with that for a while and see what you come up with, you should end up with a much better result

Neil
www.delta3d.com
https://twitter.com/frescalus

Quote

# 3 26-09-2005 , 07:53 PM

Registered User
Join Date: Sep 2002

Location: Minnesota, USA

Posts: 3,709

VEY good answer Razor, man you are batting 1000 today!

2 more ways to try:

Spline IK, kinda messy, but it worked for me for a rope sim.

and

A Simple softbody curve with the exact method you used with point constraigning rigid body objects, however, add more of them to make it look like one of those old plastic segmented jump ropes the kids have.

Then turn on collisions for the cubes, and in theory, nothing should intersect.

Play with it and get back to us!

Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com

Quote

# 4 26-09-2005 , 08:22 PM

Registered User
Join Date: Sep 2005

Posts: 21

I'll try these new ways at the end of this week.
I'm meeting two deadlines these next days, so the elevatorcable must wait a bit. But I'll get back with info on how it went.

Maybe even eith a review of it.

Quote