I would like to repulse (vs. bounce) particle from a mesh surface.
I know how to bounce particles off mesh, but Attraction with negative charge and/or negative scale does not work.

Dave Rindner

Hi David,

I can't say I have any solution, but may I ask what kind of effects you are looking for? Occassionally, simply giving it a negative values to any kind of force related operators may kind of works. Have you looked into Interact POP?

Take care,
A.

I got it under control, with a little help from Steve Ong. I am working on a car commercial, my fiirst production job with Houdini where I am TDing (i.e. I am doing all CG).
The spot is mostly live action. MOKO camera will film the car and some greenscreen practical water spray. I have to create CG rain (that matches prac. efx rain) but the CG droplets cannot touch the car. They are reppelled by car's presense. The jist of spot, is that car is so great that even nature does not want to harm it. I had junior modeler build a simplified CG car. I then ‘draped’ a surface sheet over it. I am using that drape as surface of repulsion. I have other forces blowing the rain, which later I will have to match to the real fans set, so that CG droplets have similar motion to real droplets. For rendering, the CG car will provide matte and glass refraction mattes.
The shop that I work for now, liked my previous work (with MAX, LW, EI, and Maya) so much. that they threw me into senior TD position for this project.
Theres no training like OJT !

Dave Rindner