P span 2 affected b span 3 af ●--- ar i affected by t span 4 affected by u=t,=t。=t。=t igure 6.4: Example of local convex hull property of B-spline curveu=t0=t1=t2=t3 t4 t5 t6 P0 P1 P2 P3 P4 P5 u=t7=t8=t9=t10 P6 span 1 affected by P0,P1,P2,P3 span 2 affected by span 3 affected by span 4 affected by P1,P2,P3,P4 P2,P3,P4,P5 P3,P4,P5,P6 Figure 6.4: Example of local convex hull property of B-spline curve 8