Distributions of 3D X-type (blue dots) and O-type (orange dots) grids in a data-driven simulation of a large-scale coronal flux rope eruption. The plotted grids are 2D projected extreme points of J_‖, satisfying |J_‖| > 11.9 statC s⁻¹ cm⁻². The black curves are field lines traced from the initial sampling positions near the top of the flux rope as marked by the big green sphere, while the magenta ones are traced from a small region in the eruption current sheet as marked by the small green sphere. The distribution of B_z is overlapped at the bottom.