基于重叠裁剪盒的环境漫游技术

裁剪盒技术用图像式绘制表示远景，能明显提高漫游系统的性能。文中提出了重叠裁剪盒漫游技术。作者在场景中重叠布置相同大小的裁剪盒，它们相互分割成为子裁剪盒。作者按子裁剪盒保存几何数据，使几何数据的组织及访问得到优化。提出了按视线长度及夹角优化选择裁剪盒。使用分别位于视点前后的两个裁剪盒绘制远景，能较好地消除遮挡空白。提出了简单、高效的深度图像近似裁剪算法。适当限制观察视角，可以极大减少深度图像绘制量。用原型系统进行了验证。

Environment Walkthrough by Overlapped Cull-Boxes

By replacing far geometry with depth-images, Cull-boxes can improve the performance of the walkthrough system. This paper presents the overlapped Cull-box approach. In the model space this paper places overlapped and same-size Cull-boxes, which partition each other into Sub-Cull-boxes. The geometric data is organized by Sub-Cull-boxes, which facilitates geometric data pre-fetching and rendering. Cull-box selection is optimized by evaluating the viewing distance and viewing direction, which ensures more geometric rendering and better image quality. To eliminate holes in depth-image reconstruction, front and back Cull-boxes' depth-images are utilized. A simple and efficient approximate culling algorithm for depth-image rendering is presented. By restricting the viewing angle, the depth-images to be output can be dramatically minimized. The approach has been verified by a prototype system.