How to break a mesh apart dynamicly???

Discussions about simulation, hair and cloth in SOFTIMAGE©
Posts: 153
Joined: 08 Oct 2012, 19:42

How to break a mesh apart dynamicly???

Post by thorsnuts » 27 Apr 2013, 21:46

Maybe this is a better question.

How can I break apart a solid mesh into a bunch of pieces? Any kind of compounds out the to start with?

Is there a basic way to start, then I can build on it once I get familiar?

I could use the help.

thank you,

Posts: 2496
Joined: 24 May 2012, 09:44

Re: How to break a mesh apart dynamicly???

Post by Bullit » 28 Apr 2013, 00:33

There are some videos in vimeo i aslo think some sample scenes might help.

Posts: 153
Joined: 08 Oct 2012, 19:42

Re: How to break a mesh apart dynamicly???

Post by thorsnuts » 30 Apr 2013, 17:25

thank you

User avatar
Posts: 223
Joined: 10 Feb 2010, 04:36
Location: Ecuador

Re: How to break a mesh apart dynamicly???

Post by sirdavid32 » 29 Jan 2015, 01:32

Vimeo? do you have a URL? please?

Posts: 67
Joined: 09 Aug 2009, 11:41

Re: How to break a mesh apart dynamicly???

Post by Paulrus » 29 Jan 2015, 02:55

Check out Eric Mootz's free tools - the stuff about vertex islands might be useful.


User avatar
Posts: 983
Joined: 19 Jun 2012, 21:59

Re: How to break a mesh apart dynamicly???

Post by FXDude » 29 Jan 2015, 09:36

Here is from the list, to take objects or islands as they are, and then simulate them.
If you want to deal with objects.

ICE Kine - Drive From Particles

Near the end, Eric shows how to set the initial position to the original while being driven by particles.

If you would consider merging them which may be a bit easier,

Motion Tools

Main focus in this build was to implement a way of controling polygons and polygon islands with points in a point cloud. Therefore enabling users to use regular ICE nodes and Motion Tools compounds to procedurally animate such elements.


Vertex Islands

Initialize Island Data
Initializes the vertex island data.

Create Particles from Island Centers
Creates one particle for each island center.

Transform Islands
Transforms the vertex islands.

A bunch of compounds to get diverse island related data.
The compounds are self-explanatory.


Also to foreafter deal with islands,

There is a polygon Island selection filter that you can put on a button/hotkey (while also setting as a raycast or rectangle selection mode) ,

And/or as a button/hotkey, you can put a proportional move preset with a 99999999 range with consider neighborhood ON so you can freely move islands around using "M".

And/or for clusters, another button/hotkey to set selection mode to polygon, also raycast or rectangle, with the "cluster" toggle ON
(to visually select them without having to go through the explorer)
you can also toggle visibility "Unselected Clusters" (on selected objects) if some islands are clusters and others not.

To essentially treat islands or clusters as objects.
(also useful for whenever wanting to optimally deal with thousands of "objects")

If you look at the EMTools list of things, it's like an entire universe in itself. Just cant beleive mr Mootz! :)

Also for treating clusters as objects, you can also gather/sort/organise them in groups which is pretty powerful, cant beleive XSI :)

You can have thousands of objects as "one" making it considerably faster than Maya, (meaning not just for subd's)
especially considering this...

CGTalk - Softimage vs Maya - Merge vs Combine ... &t=1246626

btopf wrote:
Hey everybody,

As the title suggest I´m coming from Softimage and testing some workflows and scripts at our company. Definitely I will come with more questions in the future

I got one CAD - Car model and want to merge(SI)/combine(maya) all objects by material.

Softimage: time 25 minutes and only max. 11GB ram (python script)
Maya: 1h and max. ram 32GB and scene size 25GB (python script) irregular saved - original 1,5GB

After some research and installed Outliner Plus I found out that a normal combine of two standard cube generates a new mesh as expected but stores everything in faces.
In the normal Outline it´s not visible but in outliner plus -> Shading Groups there you can see it that the 2 combined cubes are stored with 8 faces.
And by a CAD model with thousands of objects there are a lot of generated faces from the new objects.

This makes the scene really slow and big and ram consuming is this a normal or expected behavior ?

I have done a undoFlush, delete history and a chache clear but nothing worked. Is there a other secret to get rid of it, because it can´t be after combining objects a scene size increasing happens !
Under the hood it stores the faces and increasing ram and scene size!

I have attached some screenshots from the outliner plus and the normal outliner!


ThE_JacO wrote:

FYI file size and memory footprint are very rarely related that closely except by coincidence. For your sanity don't ever make the assumption that the file size will be indicative of anything except how much storage you need

As for combining and all that, yes, Maya is an absolute dog when it comes to both performance and handling in those regards, and while the very different approach it has in how it saves component lists can be powerful and extensible at times, it never turns out to be as compact and intuitive to inspect as Soft's local properties approach to clusters and assignments when it comes to large scene objects and most of the day to day handling of large models.
Very often when we have LIDARs that will fit people will first do passes in ZBrush with its awful 4GB memory limit rather than go to Maya to see the same operations take 10 to 40 times longer and 12GB of RAM or more.

Something that will very often work, however, in reducing times and footprint is dispensing Maya from having to undo things. You can try and reduce the undo stack to 0 so that it's immediately purged at the end of an operation (it's not like you usually want to undo operations that take an hour to run anyway) and see if that alleviates the problems.
"As an online CG discussion grows longer, the probability of the topic being shifted to subsidies approaches 1"

Free Maya Nodes
btopf wrote:
Sorry for the noise I think it´s a normal behavior. I was only a little bit shocked about how maya handles big data compared to Softimage, because I was expecting the opposite.

thanks everybody
ThE_JacO wrote:
You were expecting it the wrong way around I'm afraid.
From XSI v5 on it's always been Soft being best in class for large objects, and Maya dealing a lot better than XSI with large (many nodes) graphs.

As things stand in 2014 and to a degree in 2015 it's probably the worst of the lot by far in most regards when it comes to high polycounts. We'll see next version.
"As an online CG discussion grows longer, the probability of the topic being shifted to subsidies approaches 1"