9. ????

1
9. ????ｷ????
9.1. NURBS?????
OpenGL??NURBS(Non Uniform Rational
B-Spline)?????ｷ????????????.??????????????????????
???????????.
NURBS??
K,L???????????
NURBS??
????????????,??????? 1)?????B??????????w????1????
????2)????????????????????????
2
P33
P31
P32
P23
P22
P21
P12
P20
P30
P02
P11
P10
P01
u
v
P00
x(u,v)Sx(u,v)y(u,v)Sy(u,v)z(u,v)Sz(u,v)
3
9.2. ???????
???????????,1?????1????????????.
?????????????????????.
1)????????? a)???????????
GLUnurbsobj nrb_obj (FILE file????)
b)?????????
nrb_obj gluNewNurbsRenderer()
(fileopen(鍍est.c賠)???)gluNurbsProperty(nrb_obj
, GLU_SAMPLING_TOLERANCE, 25.0) GLU_SAMPLING_TOLE
RANCE????????????????????????????
?????????(?????????????????????????????)
4
void gluNurbsProperty( GLUnurbs nurb, GLenum
property, GLfloat value ) nurb NRUBS
?????? property ?? GLU_SAMPLING_TOLERANCE GLU_DIS
PLAY_MODE GLU_CULLING GLU_AUTO_LOAD_MATRIX GLU_PAR
AMETRIC_TOLERANCE GLU_SAMPLING_METHOD GLU_U_STEP,
GLU_V_STEP GLU_NURBS_MODE_EXT
5
2)?????????
gluBeginCurve(nrb_obj)
gluNurbsCurve(nrb_obj,8,knotvec,4,
cpoint00,4, GL_MAP1_VERTEX_4)
gluEndCurve(nrb_obj)
void gluNurbsCurve(GLUnurbsObj nobj,