nicoladanese Posted March 19, 2019 Share Posted March 19, 2019 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 Quote Link to comment Share on other sites More sharing options...
nicoladanese Posted March 19, 2019 Author Share Posted March 19, 2019 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 Quote Link to comment Share on other sites More sharing options...
ParticleSkull Posted March 19, 2019 Share Posted March 19, 2019 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 Quote Link to comment Share on other sites More sharing options...
nicoladanese Posted March 19, 2019 Author Share Posted March 19, 2019 hey Alvaro! that's what I did first thing, unfortunately is not working on H17.5 Quote Link to comment Share on other sites More sharing options...
bigwil357 Posted April 21, 2019 Share Posted April 21, 2019 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! Quote Link to comment Share on other sites More sharing options...
Atom Posted April 21, 2019 Share Posted April 21, 2019 (edited) Try dropping down a pointvelocity node, after the create surface. It allows you to add curl noise or bring in your own velocity attribute. ap_fluid_velocity_042119.hiplc Edited April 25, 2019 by Atom 5 Quote Link to comment Share on other sites More sharing options...
PixelEmpire Posted April 22, 2019 Share Posted April 22, 2019 (edited) 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. Edited April 22, 2019 by PixelEmpire Added further explanation and examples 1 2 Quote Link to comment Share on other sites More sharing options...
Bog Posted April 23, 2019 Share Posted April 23, 2019 Oh, well as long as it's nice and easy now... Quote Link to comment Share on other sites More sharing options...
nicoladanese Posted April 29, 2019 Author Share Posted April 29, 2019 thanks for all the details! will check very soon! Quote Link to comment Share on other sites More sharing options...
tgybels Posted February 10, 2021 Share Posted February 10, 2021 On 4/21/2019 at 7:46 PM, Atom said: Try dropping down a pointvelocity node, after the create surface. It allows you to add curl noise or bring in your own velocity attribute. ap_fluid_velocity_042119.hiplc Hi there, I was looking to initialize velocites onto particles and your approach seemed to be very close to what i am trying to create. Can you tell me what you were doing inside the attribwrangle_INSTALL_VEL node? I'm sorry for bringing this back up again Kind regards, Tristan Quote Link to comment Share on other sites More sharing options...
nicoladanese Posted February 10, 2021 Author Share Posted February 10, 2021 31 minutes ago, tgybels said: Hi there, I was looking to initialize velocites onto particles and your approach seemed to be very close to what i am trying to create. Can you tell me what you were doing inside the attribwrangle_INSTALL_VEL node? I'm sorry for bringing this back up again Kind regards, Tristan Hey Tristan, I don't have houdini with me now but I think you can download the hiplc attached to check what that wrangle is doing Quote Link to comment Share on other sites More sharing options...
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