_n_u_r_b Specifies the NURBS object (created with gggglllluuuuNNNNeeeewwwwNNNNuuuurrrrbbbbssssRRRReeeennnnddddeeeerrrreeeerrrr).
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
Use gggglllluuuuBBBBeeeeggggiiiinnnnSSSSuuuurrrrffffaaaacccceeee to mark the beginning of a NURBS surface definition.
After calling gggglllluuuuBBBBeeeeggggiiiinnnnSSSSuuuurrrrffffaaaacccceeee, make one or more calls to gggglllluuuuNNNNuuuurrrrbbbbssssSSSSuuuurrrrffffaaaacccceeee
to define the attributes of the surface. Exactly one of these calls to
gggglllluuuuNNNNuuuurrrrbbbbssssSSSSuuuurrrrffffaaaacccceeee must have a surface type of GGGGLLLL____MMMMAAAAPPPP2222____VVVVEEEERRRRTTTTEEEEXXXX____3333 or
GGGGLLLL____MMMMAAAAPPPP2222____VVVVEEEERRRRTTTTEEEEXXXX____4444. To mark the end of the NURBS surface definition, call
Trimming of NURBS surfaces is supported with gggglllluuuuBBBBeeeeggggiiiinnnnTTTTrrrriiiimmmm, gggglllluuuuPPPPwwwwllllCCCCuuuurrrrvvvveeee,
gggglllluuuuNNNNuuuurrrrbbbbssssCCCCuuuurrrrvvvveeee, and gggglllluuuuEEEEnnnnddddTTTTrrrriiiimmmm. See the gggglllluuuuBBBBeeeeggggiiiinnnnTTTTrrrriiiimmmm reference page for
details.
GL evaluators are used to render the NURBS surface as a set of polygons.
Evaluator state is preserved during rendering with
ggggllllPPPPuuuusssshhhhAAAAttttttttrrrriiiibbbb(GGGGLLLL____EEEEVVVVAAAALLLL____BBBBIIIITTTT) and ggggllllPPPPooooppppAAAAttttttttrrrriiiibbbb(). See the ggggllllPPPPuuuusssshhhhAAAAttttttttrrrriiiibbbb
reference page for details on exactly what state these calls preserve.
EEEEXXXXAAAAMMMMPPPPLLLLEEEE
The following commands render a textured NURBS surface with normals; the
texture coordinates and normals are also described as NURBS surfaces: