A TUTORIAL TOOL FOR THE VISUALIZATION OF THE VIEWING VOLUME IN OPENGL

Abstract

This paper is aimed at lecturers who want to
teach modeling and projection basics of the OpenGL
application programming interface and to students who
want to achieve a rapid understanding of the same. The
ensemble of modeling and viewing transformation,
projection type and standard clipping planes in OpenGL
define the viewing volume. The software system described
here, dynamically teaches the influence of each of these
degrees of freedom on the viewing volume by letting
interactively manipulate all possible parameters of viewing
and projection. In order to visualize the frustum or
rectangular parallelepiped defined by the viewing volume, a
second observer is created which usually sees the same
scene as the first observer plus the viewing volume defined
by the first observer.

Index Terms ⎯ OpenGL, viewing volume, projection,
frustum, parallelepiped.