# How does one create a particle cloud that collides like real smoke?

I'm familiar with all the volumetric methods of creating cloud looking things. I'm familiar with particles from emitters.

What I really need is a cloud of smoke that moves like real smoke when an object moves through it.

I was thinking it could be done with particles emitted using zero gravity, then set a collision on them and move them when hit by an object, but I'm not sure how to set that up.

This is a very quick two second scene requirement, so I can use millions of particles if necessary.

The end effect would be like a person walking through a cloud and disturbing each particle of smoke.

• Why don't use smoke sim directly? If you really need particles, you can use smoke sim as force field for particle system. One thing that I'm not sure about in Blender, if there was some progress in collision, because when I tried wind tunnel last time, there wasn't any vorticity behind the collider. Jun 15, 2023 at 7:10
• The problem is that Blender emulates smoke using a volume shape. It doesn't actually have individual particles that collide with an obstacle. To my knowledge. Jun 16, 2023 at 3:42
• @DrTyrell: This isn't totally true - but in parts. The smoke itself does not react to collision (unfortunately) but if you are using particle created smoke and collision objects, of course the so created smoke does "kind of" react with the collision, but only as the particles do. So later on, if e.g. the smoke would be moved by wind/gravity - it would go through the collision objects [1]: i.sstatic.net/XiljB.png Jun 16, 2023 at 4:40
• I was thinking I could create a volume that distorts in shape to simulate the collision. Jun 16, 2023 at 4:44
• i am also not very experienced with smoke, but i would force fields parented to your object give a try. This might help and give that illusion. Jun 16, 2023 at 4:47

We should probably ask - What did you try and where did you fail ... :)

## Smoke Simulation

Like in my comment simple smoke sim seems to handle your needs ...

Vector visualisation ...

Here is a slice on Y axis where you can see what I mean by -no backflip turbulences ... smoke reacts on collider movement but not exactly as in a real world ... part of vorticity is missing ... but like I mentioned for your purpose it could work ...

... or you can add another Force Field parented to Collider (mentioned by Chris if I understood it right :) )

So I have to ask again - What is the specific reason you need particles. Probably add some more screens or mockups to express better what didn't wok for you and what specific effect do you expect. Thank you

## Smoke Simulation used for Force Field > Fluid Flow

Here is example with Particle system driven by Fluid Flow Force Field issuing smoke sim ...

• Such nice visualizations! I'm going to have to post a Q asking how you did those, unless you stop me because it's too 'obvious'.. :) Jun 16, 2023 at 8:27
• ... all is under Smoke Domain > Fluid Properties > Viewport Display :) Jun 16, 2023 at 8:36
• likewise! I don't know why our paths haven't crossed, recently :) Jun 16, 2023 at 17:10
• Incredible. Thank you! My need is to show a close up of a vehicle push through fog just as you have it. The effect is important to the director if you know what I mean. ;) Jun 17, 2023 at 21:55
• Great if you found it useful ... Good luck with your project 😎 Jun 17, 2023 at 22:19