This system introduces a new type of interface for 3D
drawings that improves the usability of gestural interfaces
and augments typical command-based modeling systems. In
our suggestive interface, the user gives hints about a desired
operation to the system by highlighting related geometric
components in the scene. The system then infers possible
operations based on the hints and presents the results of
these operations as small thumbnails. The user completes
the editing operation simply by clicking on the desired
thumbnail. The hinting mechanism lets the user specify
geometric relations among graphical components in the
scene, and the multiple thumbnail suggestions make it
possible to define many operations with relatively few
distinct hint patterns. The suggestive interface system is
implemented as a set of suggestion engines working in
parallel, and is easily extended by adding customized
engines. Our prototype 3D drawing system, Chateau, shows
that a suggestive interface can effectively support
construction of various 3D drawings.