I thought Id share a macro ive made to control some of my particle systems.
Like the tutorial on CustomTool I wrote, this one uses some of the same expressions in the
pCustom, but instead on pixels it does it on particles.
It basically takes the RGB vector and applies it to the particles XYZ position, rotation, scale and velocity.
I find good use for it to conform particles to displaced geometry by using the same image do displace my imageplanes
but instead use the particles Z position.
You can produce some rather interesting results by playing around with the input map and the settings.
Ive included the macro and a sample comp.
Happy p'Ing :)/>