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nicoladanese

source flip fluid with velocity

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hey!

I'm trying to emit a flip fluid with some velocity, I can add a generic velocity in world space but in my case I want to add velocity along the normal of the object sourcing...just can't figured it out yet

normal.png

vel.png

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update: since my points have all the same N I just copied it this way from point 0, but there must be a smarter way, also when points have different N

okay.png

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Hey Nicola, 

Cant you just set the v to be equal N?

the Flip source should get the v attribute from the original geo
Im still on H16 though so Im not sure how it would behave on H17

image.thumb.png.69ec6d27b48ce07e89c31d5185206650.png

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hey Alvaro! that's what I did first thing, unfortunately is not working on H17.5

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Did you ever figure it out? I was playing with this too, and couldn't get tit to work either. Trying to get that directional emmiter effect!

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Try dropping down a pointvelocity node, after the create surface.

fluid_velocity.gif.4fbcdf735ffca7fe3f402f60ffb252a1.gif

 

It allows you to add curl noise or bring your own velocity attribute.

Untitled-1.jpg.06bb814c9a679971f2ca99917fd75682.jpg

ap_fluid_velocity_042119.hiplc

Edited by Atom
  • Like 3

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Atoms response is the simplest route, otherwise

In your geo network run your geo into (1) a volume node and then into a volume vop to set up your vector direction and noise, then in a secondary tree run (2) your geo into a vdb from polygons with  like 0.1 voxel size with a fog vdb, then scatter points in that vdb.  Then drop down a attribute from volume, set it to vector and set its name to "vel" both the trees will plug into the attribute from volume, scatter goes into points to apply attribute and the volume vop into the volumes to use, then drop down a volume rasterizeattributes with attributes set to "vel" and into a Null.  You can test what its doing by using the usual volume trail sop and use the same points and volume rasterize outputs to check your velocity field.

 

Just as an NB point in your volume vop you have to bind export to "vel" with what ever noise etc your adding.

 

in your DOP network you can either use a volume source or popadvect by volumes.

Volume source: set initialize to source flip and point the sop path to the out vel null you made, also change field to match and source volume/target field names to vel.

pop advect is pre set up with vel.

 

This gives you the ability to add alot of control, and is how they went through in in the master class/ or top 10 new features for 17 if i remember correctly.

 

Below is the same applied to a FLIP Tank and emission from a geo object as mentioned using this method.

 

 

 

vel_DOPS_source_setup.PNG

vel_source_setup.PNG

CANON_VEL_APPLIED.PNG

CANON_EFFECT_ADVECT.PNG

Edited by PixelEmpire
Added further explanation and examples

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