a study on a geometry transformation method for a geometry and scene modeler by a verbal interface
The authors have developed a modeling system Do in three dimensional computer graphics (3D-CG) that, by verbal instructions in natural language, models geometrical shapes and renders the images. The former system is based on a step-by-step construction scheme using static instructions and a static display, that is, a static verbal instruction creates a static scene and an image. This static-based system scheme has a critical limitation at the conversation stage between a user and the system. In this paper, the authors propose a dynamic instruction and dynamic display methods for the modeling system. First, the dynamic display enables users to watch the animation indicating the change between the previous geometries and the next geometries with smooth transition during the execution of an instruction from the user. Second, the dynamic instruction enables users to give the next instruction before the animation ends. For those purposes, two geometrical transformation methods by affine transformation: (a) with a common difference matrix, and (b) with a common ratio matrix, are introduced and studied to generate frames for the animation. The proposed methods are implemented and evaluated by some experiments. The changes between instructions are observed naturally by the common ratio matrix method.
geometry transformation modeler computer graphics natural language animation