        function createInteractPP(this,drv,p1,p2,addVL)
            % Compute separation between particles surfaces
            % PS: This is exclusive for round particles to avoid calling the
            %     base kinematic object (a bit slower).
            %     For other shapes, the base kinematic object will be used.
            dir   = p2.coord - p1.coord;
            dist  = norm(dir);
            separ = dist - p1.radius - p2.radius;
            
            % Check if particle is within verlet dis