Porting NURBS Objects

OpenGL treats NURBS as objects, similar to the way it treats quadrics: you create a NURBS object and then specify how it should be rendered. The following table lists the OpenGL GLU functions for managing NURBS objects.

OpenGL GLU function	Meaning
gluNewNurbsRenderer	Creates a new NURBS object.
gluDeleteNurbsRenderer	Deletes a NURBS object.
gluNurbsCallback	Associates a callback with a NURBS object, for error handling.

 

When porting IRIS GL NURBS code to OpenGL, keep the following points in mind:

• NURBS control points are floats, not doubles.
• The stride parameter is counted in floats, not bytes.
• If you're using lighting and you're not specifying normals, call glEnable with GL_AUTO_NORMAL as the parameter to generate normals automatically.

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