source files: [xc]shp.[ch]
(XG.3D-INSERT-GRID :THING <thing> [ :U-POINTS <num> ] [ :V-POINTS <num> ] [ :TRANSFORM <xtfm> ] [ :X <num> ] [ :Y <num> ] [ :Z <num> ] [ :SCALE <num> ] [ :SCALE-X <num> ] [ :SCALE-Y <num> ] [ :SCALE-Z <num> ] [ :WANT-HOLES t ] [ :RED <num>] [:GREEN <num>] [:BLUE <num>] [ :RED-B <num>] [:GREEN-B <num>] [:BLUE-B <num>] )
This call inserts a :U-POINTS-1 by :V-POINTS-1 chessboard pattern centered on :X :Y :Z. The board lies in the X-Y plane, and is of unit length on a side before SCALEing.
The <thing> must be a 'thing' in the :DRAW <camera> sense, a disembodied propertylist containing a :POINT-RELATION, and also a :FACET-RELATION. Both must be rank-1.
This call inserts points, linesegments, triangles, or rectangles, according to the nature of the thing provided. (For example, if the thing has :FACET-0/1/2 but not :FACET-3, triangles are inserted.)
If :TRANSFORM is supplied, it must be an instance of CLASS-MATRIX44, and will be used to transform the chessboard exactly as if by XG.3D-TRANSFORM-THING.
If :WANT-HOLES is set non-NIL, every other triangle/rectangle will be dropped out, in a checkerboard sort of pattern.
If :RED/:GREEN/:BLUE are specified and :POINT-RED/GREEN/BLUE or :FACET-RED/GREEN/BLUE are present in the thing, they will be set as specified (0-1 range).
If :RED-B/:GREEN-B/:BLUE-B are also specified, then if :POINT-RED/GREEN/BLUE or :FACET-RED/GREEN/BLUE are present, then alternate points/facets (in a checkboard pattern) will be set to :RED/:GREEN/:BLUE and :RED-B/:GREEN-B/:BLUE-B.