Is it possible to use a rigid body in a smoke simulation so that the smoke goes around the body.. basically the rigid body would be displacing the smoke. I have tried this with some basic poly shapes that I created in houdini but the smoke just goes right through it.. is there something else I need to do to the geometry to make it handle the smoke or is this not possible?

Thanks for any advice.

Any rigid body will interact naturally with the smoke.

Thanks.. well I think its an issue for me because I am using imported geometry. On another forum someone mentioned something about thickness but I can't seem to figure out which SOP this would be for as I don't see a thickness SOP.. so I guess I need to add thickness to my imported object to make it work in the smoke simulations.. any info on this is greatly appreciated.

Controlling thickness is to polyextrude all the faces. Make sure that you keep points shared (by normals) and check on output back in the options tab of the polyextrude node.

The extrusion doesnt have to be thick, just enough to make a volume for the collision data to be caculated.
When you send the mesh to DOPS, be sure to go into wireframe in the viewport, and look in the collisions tab on the rigid body, and turn on Show collsion guide geometry. Then adjust the samples to make the red collsion suface match as close to the original geometry as you can.

You can turn off volume based collisions inside this area, and not have to worry as such about having a volume for collisions, however I would advice against this, as simulation times are greatly affected, and not for the better.

No thickness…
http://i24.photobucket.com/albums/c44/ragupasta/no_volume.jpg [i24.photobucket.com]

Has thickness…
http://i24.photobucket.com/albums/c44/ragupasta/has_volume.jpg [i24.photobucket.com]

Collision guide geo….
http://i24.photobucket.com/albums/c44/ragupasta/collision_guide_geometry.jpg [i24.photobucket.com]

Can someone please explain rigid bodies to me... I thought I understood until I saw examples; if a rigid body does not deform when a force is applied, how is smoke, water and fire rigid bodies when they all deform,in my opinion when force is applied

Rigid bodies are exactly that. Rigid, non-deforming geometry.

Smoke, water are fluid simulations. You don't need to overthink it.

1) dropping a brick on the ground is a rigid simulation.
2) pouring a glass of water is a fluid simulation.


L

@lewis_T thanks alot my friend