du and dv are number nodes, and m is a typeless node to which the rows of the matrix of data points are connected.
In the C++ class hierarchy the class created by the NUBGIS keyword is derived from a general trimmed nurbs surface class (see TNURBSURF, 6.7.22), so that it can be used at any places where a trimmed nurbs surface is expected (with the same number format and control point type of course)
The following variations of this keyword exist (some of them define the same internal structures, and are only defined to allow consistent naming conventions):
Keyword | numbers |
NUBGIS | float |
NUBGIS_F | float |
NUBGIS_D | double |
NUBGIS_F_E3 | float |
NUBGIS_D_E3 | double |