replacing areas of velocity in a flip fluid

[craigthailand]

I am trying to make a flip fluid follow a volume field without replacing the whole containers velocity.

I basically want the fluid to stick/follow the object if the volume density is 1 and as the density gets lower gravity and other forces take over.

I've tried to use source volume and gas linear combination but forces only seem to work when velocity is added which makes them move to fast. Set to copy the fluids move at the correct speed but forces don't have any influence.

If anyone has any ideas or samples it would be much appreciated.

thanks

Craig

[ikarus]

Use a gas field vop, you can use a twoway, wired so that it only uses the volume fields values if the length of that value (speed) is above a certain threshold.

[craigthailand]

thanks ikarus, i'll give it a try.

[craigthailand]

I am a bit confused how I should wire this up and how do i get volume field "newvel" into the gas vop.

I am wiring the gas field vop directly into the 3rd input of the flipsolver .Also I only need to bring vel in as a parameter and use vel as the output.

sorry for dumb questions but its been a while(years) since I had time to dive back into houdini.

[craigthailand]

I am posting a picture of my vop net .

[craigthailand]

I am posting a picture of my vop net .

[craigthailand]

I think I have got what i wanted using a sop solver as i couldnt get the gas field vop to work . I did it the same way ikarus suggested but i used a mix and clamped the bias instead of a 2 way . I would still be interested to know what would make gas field vop work.

thanks

Craig