Pyro velocity field question

[catchyid]

Hi,

In regular RBD simulation, you can add a velocity drag (i.e. v= 9.0 v) to slow down moving objects (to simulate air resistance for example). However, in Pyro, I don't find any similar concept for smoke velocity ALTHOUGH smoke slows down automatically in a simulation (i.e. without adding velocity drag node for example, smoke slows down). My question: is there a way to change the rate of this velocity drag behavior? why there is no clear smoke velocity drag parameter like pop or rbd dop networks?

 

Thanks

[evanrudefx]

Are you talking about the gas damp microsolver? This is what I use to add drag to pyro sims.

Edited February 19, 2018 by ejr32123

[woodenduck]

You could add a GasFieldWrangle piped in to velocity update with @vel *= 0.9; in the vex snippet parameter. 

You could add a gasFieldVop piped in to velocity update. Bring the vel field in with a Bind Vop and multiply 0.9 (or whatever drag rate you want) before adding a bind export set to vel.

You could add a gasDamp Dop. This would also get piped in to the velocity update input on the pyro solver. 

You could also try playing with the viscosity parameter. This has the effect of blurring out the vel field which will give you a kind of drag. Depending on what you are trying to achieve. 

[tamagochy]

I use dragforce for it))

[catchyid]

thaanks guys

[benne5]

Similarly, you can also scale velocity on your source volume node inside your DOP net.

[lavitz01]

You can use the gasdop or you can add a vectorforce through a wrangle. I can find my file later tonight and give you specifics later if you need.