random particle detach from surface

[rochre]

Bit of a newbie here so please pardon if this is obviouse. 

I want a series of particles on a surface that randomly detach and float upward as the surface distorts. 

I know how to scatter the particle on a surface, but having them randomly detach and be subject to forces is the stretch for me.

Thanks.

[Sepu]

Have a look at this 

is basically the same. You can attrib transfer or just noise that goes from black to white, there are many different ways to do the same thing. The important thing is to have the pop wrangle getting the attribute into DOPs.

 

[rochre]

Awesome.

Thank you, Sir.

[rochre]

So I'm feeding the pop wrangle into a pop wind per the example file. The VEX appears to use an external volume to add to the pop wrangle, but I want to run some VEX that will add particles randomly to a group over time. So I guess I need to say at current time add random particle number to group.