Hi people,

I posted the same question in apprentice area but without answer, maybee this is the right place.

I'm wandering how to make an emission of particles or smoke drived by a texture
for instance I create a withe noise map and I project this on a surface and after this I want to make emission happens on the withe zones only, taking care also of the gradient.

Check this : http://forums.odforce.net/index.php?/topic/10663-how-can-i-emit-particle-from-the-turbnoise-node-white-area/ [forums.odforce.net].

thanks Swann

your link covers exactly what I'm looking for
by the way the example file has a VOP and generates a randomized texture inside this, nothing bad but if I want to paint the withe areas how can I make the VOP use these datas? I have no experience in VOP.

I did it Swann

no VOPSOP needed, just crete an attribute before the paint sop, activate the “override color” and use the attribute name just created, after the paint use a “promote attribute” and convert from Point to Primitive.

After this into popnet/source set emission to “surfaces (attribute)” and put the attribute name into the “distribution attribute” field.

that's it

by the way both the solutions are very useful, thanks again for your help