
My recent work on smaller scale residential buildings provided the opportunity to develop the technique.
Traditionally in Revit roofing tiles have been represented by a "roof object" with a surface pattern and thickness. The line-based families I had previously created for hip, ridge and rake tiles are great for enhancing 3D views and also elevations to some degree, but these views were still very "flat" - resulting from the imported surface pattern (displayed at an angle) and the lack of definition of the foremost edge of the roof material.

Pattern-based curtain panels are capable of stretching and deforming over complex surfaces. In addition, panels are automatically trimmed along angular edges, which is essential for accurately depicting the hips and valleys of these roof types.

In the building model roof structure and plywood are separate objects. The roof tiles are hosted by an in-place mass family. With the workplane set to the surface of the plywood, a boundary line is drawn offset by a few inches from the edge of plywood. The purpose of the offset is to eliminate overlapping tiles. Use 2 inches at hips and edges, 3 inches at hips and valleys.

Go to the Files & Families tab above to download sample files.