Hi there, Is it possible to get water nParticles to accumilate on a piece of geometry and build up as time goes on?

What I want to achieve is something like tiny water droplets being attracted to an object and building up to a layer of liquid surrounding the object, then after a while the liquid gets pulled away from the object in larger blobs by an invisible force. I have tried to get this done by having an invisible sphere emitting the water nParticles inwards which works fine, but I can’t seem to get the particles to attract towards the geometry: should I use an expression or a field or something like that to get this to work?

any suggestions would be greatly appreciated, this is wrecking me head here :S

I think one idea that might help in moving forward would be to try to break up the effect into components to give you more flexibility as you develop it...and also make it a little less it less of a mind bending challenge.

You can have the particles emitted towards the object then also have particles emitted on the surface of the object which will give you the impression of the particles covering it. You could use the same particleShape from each emitter so that you can use a blobby surface and heighten the idea of the particles building up. Just use the emitter ID on each particle to apply expressions to the different parts of the effect.

I think the breaking up of the liquid shell should be pretty easy to apply to the particles that you had emitted from the surface just add an attribute to the particle to key when you want things to start breaking up with an expression...or you could try using a field (or fields) to push them out.
You should be able to get some nice blobbing effects using the Stickiness properties and enabling Liquid Simulation.

These are a lot of ideas just sort of thrown out there.
Let me know if there is anything interesting in here that you may have any interest in/questions about.
All the best.
~Ben

You should use particle goals. You can use them to attract particles to geometry and subsequently make them slide along the surface. Read User Guide > Dynamics and Effects > Dynamics > Particles > Goals

Thanks a lot for the replys Ben and Michiel, I tried the method you suggested Ben and it is a good work around to have the surface emitting the particles and have the sphere outside the cameras view emit particles towards the geometry with a lifespan just enough to reach the surface and setting the surface friction to a high level.

Michiel, goals was exactly what I was looking for , it works like a dream :D As per usual with Maya all the information is in the Docs, its just knowing where to look.

Again, thanks a lot :)