Pyro Cloud emission follow velocity of emitter object?

[cwalrus]

Hello -

 

I have an object flying through the air - when it lands. POOF, i need some snow / clouds to squirt off it. I have a pyro sim that does just that - but I'm wondering how to have the pyro sim inherit the velocity of the object in the same way you can have particles inherit velocity?

 

thanks!

 

[bluciensky]

Do you want your pyro simulation to be affected by the object's velocity?

 

- then just use the moving object as collision geo (static object with transform checked), this would be easiest way...

 

or you want your source volume for your simulation to already have the initial velocity from the moving object?

 

- add velocity fields that has the velocity of the moving object, and use it for your simulation.

Edited October 20, 2015 by bluciensky

[cwalrus]

yes - the second one. That's exactly what i want to do -  How do you add velocity fields in that way? 

thanks blu

[bluciensky]

There are multiple ways of doing it.

 

How does your source looks like?

 

let's say you have a moving object with point velocity(if you don't, just put down 'trail' to make). Drop down vdb from polygons (or vdb from particles, if your source is from points or something) and

check 'fog VDB(density), and add Attribute 'point.v' below. 

 

Make your VDB name 'vel', and now if you MMB on 'VDB from Polygon' sop, you will see 'density and vel. This vel fields should have the initial velocity.

 

To check if the vel fields's working. Put down Scatter SOP under your VDBfromPolygon.

 

Then put down volumetrail SOP. Plug the scatter on first input, and your volume from VDBfromPolygon onto the second input.

 

Type 'vel' on Velocity Volumes parameter. And you will see that the trail looks like your velocity.

 

In the DOP network, in Source Volume. Put '100' on Scale Velocity parameter to test if that's working. If it works fine, you can just find a good value for your simulation.

 

Well, this is a rough  explanation and just one of the methods...! so yea, there are other ways to do that as well.

 

 

 

 

 

or you can just put your own velocity value that is similar to your moving object using volume vop or something

Edited October 20, 2015 by bluciensky

[anim]

you can as well just start with using Pump From Object shelf tool from Populate containers Shelf

(if your object is animated on object level, you will need to check Velocity Volumes/Object/Add Object Motion on create_v_volume node it creates)

[cwalrus]

You guys are awesome - thank you for helping.