LC #42 Pipers Alley

View Full Version : softBody on splineIK

03-04-2003, 06:50 PM
Hi all

Ok.. here is my next little problem.

I'm trying to put a pendant on one of my characters.
I have 3 joints for the pendant and I really like the way it looks like when I add a spineIk and convert it into a soft body.

Now.. as you can imagine, I get crashing problems.. so how could I get around the crashing part?

Ok.. so that you can have a better idea of what I'm trying to do here it goes:
I'm working on a game, where we already have like 1500 moves done. and we don't really want to go back and animate 3 joints for all the moves.. that would take way too long. So that's why I wanted to automate the pendant (we used to have the pendants as part of the body mesh)

Any ideas? could I restrict they movement of the pendant? so that it moves one way but not the other?
I can't put limits on the joints since they are not really doing rotating by themselves.. they are following the spline..

I guess I would like to put limits on the CVs (not particles since I converted them to softbodies)

Thanks for the help


03-04-2003, 06:52 PM
Heya goosh,

can you use cloth and use that to drive the splineIk as a wrap deformer?

03-04-2003, 08:10 PM
Hey Jason

humm... no.. not really.. we are trying to do it as simple as possible..

The other thing is that we are exporting everything from Soft (what we used to use) to Maya (so that I can figure something out) and then export it again to XSI (what we'll be using)

If I can find a simple way in Maya, then it can be exported to XSI, but I have a feeling cloth wouldn't be able to export.


03-05-2003, 01:19 AM
Hi goosh,

Ok, something I have to ask, you mean the pendent is coliding with the main body, (not the computer is crashing.)?

So if the curve is a soft body? Then maybe could you add springs to to the curve on the (particles/cvs), and make them a collision object with the main body. Then after that is done, bake the animation of the joints so they are keyed at everyframe, and then export?

Just guessing here really, that's what I would tend to try.

But I do feal intimidated sinse Mr.schleifer literally wrote the book on this and his way of doing it will probably be ten times better then mine :)

03-05-2003, 01:24 AM
Yeah.. that's kind of what I've been trying to do..

But now I realise I've got another hurdle :(

Since I'm working on a game, I need the first and last stages of the pendant to match.. and if I'm doing it dynamicaly it's going to 'cause quite a bit of pain.

I'm thinking that in the end (sadly enough) we would have to key all the joints in FK for all the moves :(

I think that trying to automate it would cause more headaches than anything else


03-05-2003, 01:51 AM
would rigid body dynamics work? they will convert to keys prolly better than a softbody......

just a thought,


03-05-2003, 02:40 AM
I just did a little experiment on this (figured it couldn't hurt), I didn't even need to make springs. I could make the cvs/particles, collide with an poly object very easily. So what I have now is my three joints, colliding with a moving ball, with the joint animation be driven by the IK spline parented to a locator.

Anywho, if the animation has to be on the joints for exporting, thats the part I get stuck well???

But I have a little scene file with the joints coliding great with a poly object if you want that, just I can't think off the top of my head how I could transfer the animation to the actual joints for exporting.....:shrug:

hmm...there has to be a way brain just dosen't want to think of it at the moment though..arghhh :D But if you got the animation to the joints, looping them for the game would be pretty easy by just using the simplify function in the graph editor, and making a little bit of tweakage to the F curves.

03-05-2003, 06:52 AM
just bake the animation on the joints by selecting them and using Edit-->Keys-->Bake Simulation

bingooo! :)

03-05-2003, 01:03 PM
doh! How embarrasing :) I totally forgot it was in the edit menu.... I was looking in the solvers menu for some strange reason. heh..can you tell I haven't used dynamics in

Thanks Jason.

03-05-2003, 06:39 PM
Cool stuff..

Yeah.. I got the collision object working.. but still, my biggest problem is the fact that it's a game, and all the moves have a start pose and an end pose and the start of one needs to match the end of the other, etc..

If I use dynamics, then these poses won't match :( so I'll have to do a lot of tweaking to get it going...

Also, the characters do a lot of flips, etc.. and sometimes it looks weird.. so I figured we'll just FK everything... it's ok.. after all.. it's not me that one that'll do it :D

Thanks for all the help.. if anything, I learnt quite a bit about dynamics :)


03-09-2003, 06:45 PM
This is a tired brain talking so please:-)), but couldn't you animate the goal value to achieve the in and out poses???


03-09-2003, 06:58 PM
Hi pigbelly

Yeah.. I thought of that too, and I think that might work nicely.

We did find a really cool sping plugin for SXI that works great.
So we'll probably end up going with that.. it's pretty sweet.

Thanks to everybody for their


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