Hello,

I was hoping someone could chime in on a ‘behavior’ I've noticed with using geometry as a static object for collision with a smoke sim.

I've reduced the ‘problem’ from my original file to this one I am including here.

The geometry I am using is one where it has a hollow interior where the smoke fills.

Initially I made the walls of this container very thick to ensure no smoke passes through the intended barrier.

This idea came from reading several posts about people having too thin an object so that some smoke ends up passing through.

I've sort of had the opposite effect.

It seems that by making the walls too thick it changes the interior boundary that the smoke sees.

The result is that the smoke can't fill the entire chamber.

I've used a revolve node to make the geometry from a profile and looking at the scene in wire mode doesn't reveal anything that I could be doing ‘wrong’ in my construction of that geometry.

In the file attached I have a switch node that alternates between the 2 net box set of nodes.

Each netbox creates the same hollow interior sized chamber.

Each one differs in the size of its exterior.

And as said before the one with the larger exterior ( thicker wall ) doesn't allow the smoke to fill entirely in the interior.

Yet the smaller thickness walled geometry (netbox 0 - switch paramter set to 0 in the geo node “Smoke_Boundary” tab Switch ),

allows the smoke to fill to the end of the chamber.

I was hoping someone knows what is going on here as it would help me decide what to do in my original file.

In the original file I import a profile to use as part of constructing the chamber. That imported geometry is based on a dynamicly changing curve shape.

So not knowing whats going on in creating the geometry leaves me in limbo of what to do in deciding how to create a function that determines the thickness of the wall other than just going with the idea of making it thinner and leaving it to chance.

If of course if the thickness is what the source of the problem is, maybe there's some glaring oversight of something on my part.

Thanks to anyone who may be able to offer insight about this.

Side Note - before I got to this point of trying to find out what's going I spent alot of time playing around with adjusting ‘voxel’ size and padding. Both of which do not seem to affect the result.