circular gravity in softbody modelling

What I’d like to do is softbody model a ring inside a cylinder, so that the ring “falls” from a central axis to lie snug against the inside of the cylinder.

Can this be done in Blender? Basically I don’t want a perfect fit (or I could just pop it in there flush with the cylinder wall), but an organic soft body looking effect. But I’m wracking my brain trying to figure out how to do it with gravity only effecting things in one direction.

Any input would be greatly appreciated.


I’ve attached images to show you what I’m actually trying to do. You can see this is a big hollow S, with the faces facing in (it’s a game level). In the second pic you can see the “water” object that’s been soft body collided with the inside of the S. It has the kind of look I’m going for.

But what I’d really like to do is have it ring all the way around the inside of the S, or even wander around the top, bottom and sides of the S.


this might be an idea (I have not tested it though):

  • model your ring (w. e.g. a torus primitive)
  • make it a softbody
  • add a lattice (or a slightly larger torus)
  • apply lattice modifier (or meshdeform) to the ring
  • scale the lattice (or larger torus)

(this sounds a bit complicated, but i think that just scaling your ring might not work: if it passed the edge of the cylinder, the ring might just collapse).

BTW: make sure the normals of the cylinder are pointing inwards otherwise the collision acts wrongly.

Hi varkenvarken,

Thanks for the idea. I’m a little confused though–what makes it collide with the S object?

I did a little test case with cubes, and got a solid body collision going fine. The I added a lattice and made it the parent of the softbody cube. But when I scale the lattice the cube grows beyond the colliding surface.

Anybody? Am I missing something obvious?