zpξOstxySqpviewing directionp(a)pK < 0(b) pK = 0n1<> 0n= 02(c)pK = 0kn = 0k1n2= 0(d)K > 0kkCNTp(s)viewingdirectionpprincipaldirectionSCmaxDe2peφ1minviewingdirectionmaxdecreaseincrease(a)CmaxDe1e2viewingdirectionmaxdecreaseincrease(b)minlqrl’CQξ’sT (S)pp(a)T (S)pprQξ’(b)T (S)prQ’pQξ’(c)s’sr’ξsξxgenerating curvepymeridianzparallel(a)ll’q1/kp1/k’q’p’C(b)viewingdirectionPTLξp∩S PPoint #0e0.04ruta0.03vruC0.020.010V1V2Viewpoint (radians)V36.280.04Point #5eru0.03tavr0.02uC0.010V1V2Viewpoint (radians)V36.28Point #6e0.05rut0.04avr0.03uC0.020.010V1V2Viewpoint (radians)V36.280.028Point #0eru0.021tavr0.014uC0.00700V1Viewpoint (radians)V2V36.28Point #1er0.021utav0.014ruC0.00700V1Viewpoint (radians)V2V36.28Point #50.028eruta0.021vruC0.0140.0070V1Viewpoint (radians)V2V36.280.035CurvatureCurvature0.0210.0280.0210.014020406080100Viewpoint (frame #)120020406080100Viewpoint (frame #)120N(p)T (S)ppw(s)VTviewingdirectionchangeN (S)pTNp∩pS N (S)T (S)pSpVrimTp’lφl’ξviewingdirection
