1. NURBS
LWCAD supports standard NURBS curves and surfaces.
Nurbs curves and surfaces are implemented in LightWave as Polygon Handler plugins.
NURBS Curve 2
Polygon Handler type name: CUR2 (listed in Polygon Info panel)
Latest version 2 is fully compatible with previous curve types from LWCAD 4.5 and older.
Older curve types are automatically converted when object is loaded.
Lines and curve segments can be joined into a single poly-curve.
Closed curves are supported.
Examples listed below:
NURBS Surfaces
Polygon Handler type name: WSUR (listed in Polygon Info panel)
Two basic surface types:
flat (F surface)
defined by single or more curves
first curve defines island, next curves are holes
all control point positions must lie on the plane (same as polygon)
nurbs (N surface)
defined by 2-dimensional grid of control points with weights
control point positions are not constrained
surface can be closed along U or V direction
surface can have 2,3 and 4 edges
holes are not supported yet
Examples are listed below:
