box spline 3x curvature 2x curved sections 2x curves 2x curves and surfaces 2x quadratic super-splines 2x attribute curves 1x bernstein-bezier techniques 1x curvature estimation 1x curve interpolation 1x curved edges 1x disclination 1x feature curve extraction 1x flowline curvature 1x intrinsic laplacian of curvature 1x line of curvature 1x parametric curves 1x roc curves 1x space-filling curves 1x spline 1x spline patches 1x