Shapes have surfaces that are like other Surfaces in PhotoModeler. These surfaces are called Shape faces and they can be textured and surface-drawn on (see Surface Drawing for information on drawing points, lines, and curves on the plane of a surface in one photo).
Other types of surfaces (Path, Loft, etc.) can be attached to Shape Edges just as they can be to lines.
Individual faces can be hidden so the interior of the shape can be seen. Also the faces can be turned inside out (so they face inward instead of outward - important for texturing an interior such as a room model). See Properties Pane and Shapes Properties for information on setting various properties.