Softbody collision trouble

[3dg]

using splines as softbodies is cool because they render quickly and you can use realtime generators with them (such as the various NURBS objects, and possibly even Paul's solidSplinePro)

But the problem is that collision relies on vertices. You'll need a fairly high point count on your spline to make it work (assuming that spline collisions are actually even calculated at all.) And I mean actual points, not the "in between virtual points" that Cinema adds in to smooth things out.

*EDIT*

well, I just ran a test, and it appears that softbody splines will not react with rigid body objects. I can think of a way you could do it, but it wouldn't be much fun...

Using xpresso, attach each point of your spline to a unique null. child these nulls to small spheres. Set the spheres to editable then set them up as rigid bodies. (this is not the right order...do the spheres first and make them editable, then put nulls in them, then finally use xpresso.)

That should work. You might have to up the subsamples to get the collisions detected with the small spheres.

HTH

Gary

[Kirl]

Thanks for the reply...!

I can't believe Maxon didn't include this. This means that dynamics is pretty much useless for hair also...

Ah well, I guess I'll try your Xpresso suggestion (as if shreks bone collision system didn't already make my head spin), If somebody can provide me with such an expression I'd be eternally gratefull.

I'll take a look if meaby Shrek's got something as simple as this. ;)

[Kirl]

I just saw a picture in the dynamics manual on page 237, where a softbody is coliding with a sphere. Seems to be pretty much what I want, only vice versa; The cloth should be rigid and the sphere soft. I can't think of a reason why a spline should act any diffrent than poly's with the same tag.

So meaby it is possible afterall...?

[wuensch]

the explanation why it does not work is pretty simple (though I too wishes it was different):
The colission detection of Dynamics sucks.
It works only with polygons because it needs the Normals (with severe problems with deformed polygons which render it useless for characters).
And since a spline has no poly---
The suggestion above with the colission spheres might be an interesting sollution--
You could save a lot of clicking in Expresso by transferring the objects locations to the splinepoints with the help of the LinkList operator in Expresso---

Olli

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