Hello, I'm having some trouble trying to transfer ‘vorticity’ from a flip simulation to my meshed surface. The Particle Fluid Surface node has an option to transfer vorticity, but I just don't get any attribute on the mesh. I can visualize vorticity when I enable ‘visualize mask’ but nothing else.
Do I need to enable something else somewhere?
I can calculate this using attribute vop but maybe this is what the ‘transfer attributes’ option should do? a bug, maybe?
I am having the same problem, I may have a solution. In your flipsolver go to particle motion tab, vorticity tab, there is a check box add vorticity attribute. When I checked that I can now view the vorticity in the particle fluid surface in the output section you can visualize velocity and vorticity. Hopefully this helps. I am still struggling with how to do velocity and vorticity pass with flip fluids as well.
I can help you with the velocity pass. Dive into your liquid shader (basicliquid?) and create a bind node, set name to v and override type with input. Then connect a length node, followed by a fit range, a ramp parameter (where you can choose the colors for the pass) and connect that to a Parameter node, set its name to v and from the Export drop down menu, select ‘when input is connected’.
Then in your mantra ROP, select the Images tab > Extra Image Planes tab > and create a new image plane. Set VEX variable to v and vector type.
And that's it. You can render vorticity (a float value).
Really glad that helped out. And thanks for the info on how to get velocity pass. I must be doing something wrong though. I followed your instructions, but I am not the most familiar with Houdini. I posted a scene file if you could please take a look at it. I would really appreciate the help, as I certainly need it. Also when you set up a vorticity pass is it the same procedure. Feel free to change anything on the file. Thanks again.
