Shaded Polyline

The shaded polyline is a special 3D object that is fully defined through its arguments. It is distinct from the normal polyline in that it is subject to the current lighting, material and texture mapping settings and is distinct from the other objects in this section in that it is not constructed from facets.

The routine to draw such a polyline is:

where npts are the number of vertices defining the polyline and points and normals are arrays of type GPOINT3 which define the coordinates and the normals at each vertex. An optional argument gTextCoords can also be supplied if texture mapping is to be applied to the polyline.

The shaded polyline is useful where linear detail needs to be added to a scene with objects and/or surfaces and where the detail needs to respond to the current lighting conditions. It is important that the correct normals are supplied with this routine, usually indicating the normals of the associated facets on which the detail is being added.

Note that all other polylines, polygons and rectangles are drawn with lighting and texture mapping switched off and thus appear in their specified colour.