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Smoke strange behaviour (when scaling 'collision' type objects)
Closed, ResolvedPublic

Description

System Information

iMac
NVIDIA GeForce GT 755M 1024 MB

Blender Version

Broken:
I think the version is irrelevant in this case, as I tried it in various recent versions, and the problem is consistent.

Description of error

Smoke simulation starts to behave very strangely when I try to scale the 'collision' type object.
I've capture this video showing exactly what I'm talking:
some_bug.mov

Sorry if I'm using this channel the wrong way, but I really tried to find the answer to this problem before, and it seems nobody else have faced it. Maybe I'm missing something, but I don't know what. So, if it helps, here is also the .blend file with the simple setup you can see in the video:
smoke_bug.blend

Thanks for your attention!

Event Timeline

Hi, this is not a but, Blender try to recalculate smoke during scaling/moving thats because you get artifacts in 3Dview.
After finish scaling/moving all work as expected again.

Cheers, mib

I think its a bug, too.
If you rotate any smoke-collision-object around its z-axis, the same thing happens.
Thats often a problem when you want to use RB´s as colliders in a smokesim.

the smoke sim doesnt handle scaling, all object scales should be applied.
not sure if it is a bug, its always been that way.
Think of smoke as an advanced cycles material.
if one scales the domain, then also the smoke doesnt change, as a material it only stretches.

But rotating around any axis should not be a problem. Limiting a smoke-collider-animation just to movements without rotation is no deal.
Using rigidbody-smoke-colliders is actualy a problem- when there is the too much rotation the smoke puff´s like in Deny´s Video.
Ill attach a video: https://www.dropbox.com/s/k7da62vhc2omp8d/SmokeBugs.mp4?dl=0

Not sure where this instability comes from (clearly something fishy is happening in the velocity field), but this was already submitted and archived since no active developer is working in that area.