3D Model Annotation from Multiple Viewpoints for Croquet

This paper explores ways by which multiple authors can annotate 3D models from multiple viewpoints in a 3D collaborative environment, with particular reference to the environment provided by Croquet. We deal with two types of viewpoint: the conceptual viewpoint and the physical viewpoint. Our approach is to exploit the portal, which is a notable feature of Croquet, in order to achieve our goal. We can assume that a physical viewpoint is expressed by the position and orientation of a portal. To provide a method for annotation based on the conceptual viewpoint, we developed a new portal called an "interactor". The design and our preliminary implementation are discussed