层次深度拼图集一种新的树木快速绘制方法.pdfVIP

第 9 卷第 10 期 中国图象图形学报 Vol. 9, No.10 2004 年 10 月 lournal of Image and Graphics Oct. 2004 层次深度拼阁集:一种新的树木快速绘制方法 玉 青 张淮声 华炜 鲍虎军 (浙江大学 CA DCG 国家鼓点实验室.杭州 31002 7) 摘 要 提出了…种居次深度拼图集的树木表示方法，可以快速绘制树木，并有较高真实感效果。首先对树模型进 行采样，得到其 LDI 集，然后使用…种包含遮挡信息的自适应纹理压缩方法，组合成纹理图像包，并创建对应的深 度拼图集。这样树被表示成多个采样方向上的层次深度拼图集的组合。在绘制中，使用一种融合策略进行绘制合适 的居次深度拼图集，实现了渐进过渡。通过实验，可以使用相对于树的原始面片较少的深度饼图绘制，能够满足交 互式应用的需要。 关键词居次细节层深图像深度拼图 中图法分类号: TP391 文献标识码 :A 文章编号: 1006 偏 8961 (2004 )1 0ω1216 胁。 7 LD 胁1 -Pack: A New Method for Rendering Trees Rapidly ZHANG Huai-sheng , HUA Wei , WANG Qing, BAO Hu-jun (The State Key Laboratory 0/ CAL也.cG ， Zhejiang University , Hangzhou 310027) Abstract 丁 his paper presents a new specification of LDMωPack tree , which renders trees rapidly with high fidelity. It first samples the tree model , and gains its LDI-Packs. All LDI-Pack textures are compressed by an occlusion-inclusive compression approach , and packed into texture packages. 丁hen the corresponding LDM-Packs are created from LDI-Packs according to the predetermined viewpoints. Thus , a tree is specified by a group of LDM-Packs with several sample directions. When rendering stage , one blending scheme is used to render correct LDM 翩 Packs for smooth transitions. Shown by the experiments , the number of rendering depth mosaics is less than the one of the tree original polygons. Keywords levels of detail(LOD), layered depth imageCLDD , depth mosaic(DM)