1st issue - a stable vortexField


i have a particle swarm of 50.000 with random radii. a a turbulenceField has been applied to create pattern. the initial state is now set to a dense ball-like particle cloud. the emitter was deleted. so, the particle count is a 50k, live forever and no new particles will be created. this is my start scene.


now I´d like to create some spiral shape to the particles. the problem is: vortexField(Y) blows all particles into universe. so I´d need some stablizing field or modifiy the vortexField in that way so the particles stay together and only receive a spiraling movement. my goal would be to create spiral arms but the particles don´t step outside my XZ-boundingbox. how would I start..?

any input is much appreciated. here´s the scene if anyone is interested. it´s maya2008. hope it´s not too big.


... it was, but I hope you get the idea from my description.