Mesh interaction to emit particles?

I have 2 large bodies and I would like to emit particles where they interact. How could I do this?

To be more specific, it is a big wave hitting the water in a linear fashion. As the wave goes hitting over the water, it should be emitting particles. Any idea from anyone?

Oh, and since I am asking these, how can I make particles not being emitted inside another object?
In this case, the wave enter inside the object. I have a side emitter on it already that should emitt outside the ocean, but should stop emitting once inside it.

Simply setting the ocean as a kill particles collision works for the particles already emitted outside. But as the wave enters the ocean, it keeps emitting particles…

Hmm, I thought about this when playing around with the ocean sim a while back… So I haven’t tried this myself, but it should be possible to emit particles together with dynamic paint with an intersection object and then use the painted areas as an ‘emit mask’ (so to speak) for that object. The particle and instances from the original object would of course not be rendered, they’re just used to create the ‘emit mask’ thingie…

It’s a bit to late here to start playing around and setup a scene now (3.40am here), but if you don’t get what I mean I think I can set it up quite easily. Or not. But I think so, hehe… ;D

Edit: And stuff like this will be sooo much simpler when the node based particle system gets integrated into Blender. I mean, I’d solve this in minutes using PFlow in 3ds… Node/event based particle systems is the absolute shizzle… ;D

Yup, originally I was thinking about dynamic paint. Actually, I even got it working, but did not check to see if it would animate correctly (blender particles are really troublesome with animated anything). But later on I gave up because textures on blender does not work as well as I would like and I would need many more particles. And I want to use as many as I can possibly squeeze from blender.

For now I solved it using a constant blend texture with world location, since the ocean is very planar. It is not ideal (if it was not planar it would not work) and I get most of the problems from dynamic paint. But, at least it is automatic. I don’t have to bake the textures.

Node based particles would not do much better if they don’t implement a mesh collision or proximity test. In theory, blender already has the hability to solve this, with the useful vertex weight proximity. I would solve it even faster on blender then in pflow, just creating a vertex group and setting a weight proximity modifier to be controlled by the wave mesh and setting the particle system to emit from this vertex group.

But I tried. Again, the poor forgotten particle system of blender is not compatible with this modifier. Just like it is not compatible with uv project modifier, mask modifier, animated textures, and many other things.

But… I originally attempted this with pflow in max. I could not do it there without krakatoa or thinking particles or something.


Well that buggers me and does explain a lot, I was trying to do just that, using dynamic paint to weight a vertice group and then tell particles to emit based on that vg. but since particles and a dynamic VG arnt going to ‘play well’ together for the forseable future, makes one wonder how I’lm gonna get spray from the interaction.

Apparently, particle system won’t work as you want.

This is a terrible limitation.

I did not understand your second post. I don’t think you need 2 passes for that (though I use them for other reasons). But anyway, if you can’t animate the textures, what can you do with that?