nurb:LoadSamplingMatrices(modelArray, perspectiveArray, viewArray)
modelArray, perspectiveArray, and viewArray to recompute the sampling and culling matrices
stored in nurb. The sampling matrix determines how finely a NURBS curve or surface must be tessellated to satisfy the sampling
tolerance (as determined by the #GLU_SAMPLING_TOLERANCE property). The culling matrix is used in deciding if a NURBS curve or
surface should be culled before rendering (when the #GLU_CULLING property is turned on).
nurb:LoadSamplingMatrices() is necessary only if the #GLU_AUTO_LOAD_MATRIX property is turned off (See nurb:SetProperty for details.).
Although it can be convenient to leave the #GLU_AUTO_LOAD_MATRIX property turned on, there can be a performance penalty for doing so.
(A round trip to the GL server is needed to fetch the current values of the modelview matrix, projection matrix, and viewport.)
Please consult an OpenGL reference manual for more information.