Textured virtual walls achieving interactive frame rates during walkthroughs of complex indoor environments

Presents a new approach for using texture-mapped quadrilaterals as approximate representations for objects that are far away from the viewpoint. The method is suited for interactive visualization of complex indoor environments such as CAD models of large plants. In a pre-processing stage, the 3D model is partitioned by virtual walls. These virtual walls are simple quadrilaterals which divide a large room into a set of separated cells. During the walkthrough phase, the system only renders the geometry of cells surrounding the current viewpoint. All distant geometry is culled and replaced by "textured virtual walls" representing the same part of the model as the culled geometry. A description of techniques is given for minimizing visual artifacts and for controlling the transitions between textures and geometry if the viewpoint moves towards a virtual wall. The approach makes extensive use of texture-mapping hardware. It considerably reduces the number of polygons rendered by the 3D graphics pipeline and therefore contributes to achieving interactive frame rates.