Sorry if this is covered elsewhere, if so please point me to the right spot.

How is the collide surface module used with Kangaroo? Does it feed into the geometry input? I've got P-law working to repel a set of partilces from each other. now I'm trying to use collide surface or pull-to surface to bound them within a region. I'm used to the older version of Kangaroo that has constrain to surface integrated, now having trouble understanding how to hook up.