View Full Version : Maya Nucleus - Chain/Rope Simulation by Autodesk

11 November 2009, 12:55 PM
Hi all,

I just for the first time found the time to have a proper look at the new Maya 2010 features and came across this promotional video about nucleus. (at the bottom of the page)

I think Jos Stam needs to catch some sleep, but that is besides the point. The reason I am bringing up this video is that around 2:15 a completely interactive chain/rope simulation is shown. Has anybody got any idea how this is set up? It looks very precise and fast.

I think I am aware of most of the usual approaches to create something similar, but these solutions always have many letdowns, whether it was hair/joints, particles/springs/softbodies ... this one on the other hand looks _exactly_ like what I want - stable, precise and fast.

Many thanks!

11 November 2009, 01:01 PM
on closer inspection it might not be interactive, but it still looks very successfull.

11 November 2009, 01:09 PM
hair I believe is the fastest solution to a 1 nail chain.

11 November 2009, 01:31 PM
I once created a rope bridge using nParticles and nConstraints. :)

Of course it does not hand collisions in the gaps between the particles but it was quick and fun.

11 November 2009, 02:28 PM
me too, but that intertwined rope looks too good to be true. It must be a new technique, or at least one I never tried.

11 November 2009, 01:42 AM
My guess is that is simply strip of polys. With collision set to vertex and colored yellow. and self collision set to edge and colored red. A setup like this works very well in nCloth. Because it's collision is so robust. In reality nCloth cloth dynamics are not anything crazy. However it's rock solid collision is just unmatched.

11 November 2009, 01:50 AM
Here is a script I wrote to setup quick dynamic ropes with the addition of attaching PFX Brushes to them or extruding a tube down it for texturing..

11 November 2009, 08:02 PM
That rope example is interactive and is a shot from Jos's standalone prototype. Nucleus can easily handle arbitrary linked segments with good quality thick segment collisions. Unfortunately in Maya you can can't construct simple (self colliding) chains like that currently. The edge collisionFlag on nCloth basically uses the same collisions as for that rope.

A similar, though somewhat less efficient method is to create a long skinny quad mesh strip and use this for the rope. One can still use edge collisions and set the thickness of the nCloth to the rope thickness. There are many more stretch links evaluated and 4x as many edge collisions computed, but it is still relatively efficient.
The quad mesh strip can then be turned into a rope by using as a wrap deformer or various other techniques.

Another varient might be to use a long skinny triangular nCloth prism for the rope and round it by simply hitting the 3 key.

Maya hair can also be used for this sort of thing, and is relatively fast, although it is poor at self collision. At some point it would be good to replace the maya hair collisions with nucleus ones.


11 November 2009, 03:27 PM
Thanks Duncan, I will attempt to do some tests with a cloth setup. What you are describing as "skinny" ... wouldnt it be easiest/quickest to simply use a very long plane with no thickness (i.e. only 2-dimensional) ? Is that what you mean?

11 November 2009, 04:07 PM
What you are describing as "skinny" ... wouldnt it be easiest/quickest to simply use a very long plane with no thickness (i.e. only 2-dimensional) ? Is that what you mean?
By skinny I just meant a long rectangular shape.


CGTalk Moderation
11 November 2009, 04:07 PM
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.