View Full Version : FiberFX test fail

03-06-2013, 05:52 AM

I'm trying to do a little anim with FFX and Bullet. For some reason the hair 'jumps' in several frames.

I've attached the simple scene, please look at frame 50 & 51 how the hair 'jumps'. At the end of the anim it's even worse.

Does any1 has an idea what's going on here and how I can solve this?




03-07-2013, 07:26 AM
No one? :(

03-07-2013, 10:07 AM
As I look at it, I see it failing on the rotation of the chain; it's as though there is a bone there that is getting flipped. Said another way, it looks like the points want to rotate but can't until forced; the jump is the forced action.

Not sure what to suggest outside of another path or some way to unfurl the curls.

03-07-2013, 01:11 PM
The problem is there are no 'bones' in this scene, only a simple LWCurve, FFX and Bullet. I don't rotate the LWCurve, only the camera a little.

03-07-2013, 01:44 PM
I see that but it doesn't mitigate what the math is trying to do. In trying to unfurl, it goes -against- what it thinks is the right way to be, that is to say, look at the hair as it unfurls. You will see that it has to 'unkink' itself a few times. It's that 'unkinking' that is causing the problem.

Very nice test, by the way. Beautiful if you can get this to work out.

03-07-2013, 03:50 PM
Some advices:

1) Try to work in a more regular scale scale (now the object in Modeler it's about 13 meters long...).
2) Leave at least 2 vertex without the soft weight.
3) Add the ShowCurve Custom Plugin so you can see the Curve (or convert it to a polychain, even better).

03-07-2013, 04:25 PM
I'd vote for the polychain; bet the maths is much less 'strict' in that case.

03-07-2013, 05:00 PM
I'd vote for the polychain; bet the maths is much less 'strict' in that case.

Shouldn't make any difference, really, since dynamics are calculated on the points in both cases. ;)

03-07-2013, 06:27 PM
Lino, I think you have a point there about the points. The more points, the more problems. I've just tested with polychain and curves. If you have too many points, you'll get errors.

The biggest problem is when you start to twist or braid the FFX with dynamics. Somehow it gets screwed up completely in some frames, no matter what scale you use (tried with a polychain of 15cm).

I still hope there is a way to fix this, becuase the end result in slowmotion (slow down time scale of Bullet) is great.