Velocity Field Pyro import with new volume sourcing

[rolfcoppter]

Hey guys,

I have a velocity volume that i am trying to source into my pyro simulation in Houdini 17. But with the new volume source node i cant seem to figure out how to get this working. Does anyone know how to hook up a velocity volume with the new volume sourcing in 17?

Thank You!

[pxptpw]

its the same , they have split it up for speed and convenience, as they done in previous versions for the flip fluid meshing ,

one way of doing this is , for an example,

make a tube on top of your sphere emitter (position it however you like) , say you want the smoke to move towards the created tube

copy paste the pyro source created by the pyro shelf tool or create pyro source , connect the tube to the copied pyro source, in the pyro source mode drop down choose volume scatter,

add a polyframe to after the pyro source , in the polyframe add TangentName to N, (normals facing towards the next point),

(well you could do all this in a wrangle node , but as an example)

add a wrangle and v@v = @N;

add a volmue rasterize attribute or copy paste from the one created by pyro shelf tool,

add a null after this call it OUT_vel,

in your Dop , either copy the volume source or create one , and point the sop path to OUT_vel

and connect this node to the merge node and this should move the smoke towards the created velocity

 

 

 

 

 

Edited November 27, 2018 by pxptpw

[charly]

The main idea is to use VDB instead of volume.

So you can build your velocity field with volume then transform it in VDB using "Convert VDB" and "VDB Vector Merge".

 

 

velocity_field_R17.hiplc

[rolfcoppter]

Sorry For the late reply. Thanks for all the help guys!

I did end up getting it to work after realizing i was missing a density attribute which i didn't think i needed for it to work.

I have the same question now for flip fluids though? is the method the same or is there other things you need to do when sourcing a velocity field into a flip simulation?

Thanks again

[mdharper]

On 12/14/2018 at 8:04 AM, charly said:

The main idea is to use VDB instead of volume.

So you can build your velocity field with volume then transform it in VDB using "Convert VDB" and "VDB Vector Merge".

 

 

velocity_field_R17.hiplc

OMG!!!  I have been trying to find a solution for this for months. This totally fixed the issue!