CAJ | 학술논문

针对大规模城市场景受制于数据规模，难以实现完整场景的视觉无损渲染的问题，提出一种基于过程式纹理重构和混合层次细节(LOD)模型的渲染方法。首先提取纹理中的重复与对称特征，构造纹理的过程式语法表示，实现了约70%的数据压缩，并且用户可以直接控制过程式语法的生成；然后通过几何模型采样创建点、线和多边形混合的LOD表示并编码存储；最后根据屏幕空间投影面积选择LOD模型进行渲染。实验结果表明，与原始模型和几何LOD方法相比，该方法分别实现了约10倍和5倍的渲染加速，可以实时渲染城市级大场景；在大幅度提高渲染效率的同时，基于72个个体样本的用户感知评价测试和基于动态范围无关算法的自动化测试结果证明，该方法渲染结果的视觉质量与原始模型相比无显著差异，是一种视觉无损渲染方法。
침대대규모성시장경수제우수거규모，난이실현완정장경적시각무손선염적문제，제출일충기우과정식문리중구화혼합층차세절(LOD)모형적선염방법。수선제취문리중적중복여대칭특정，구조문리적과정식어법표시，실현료약70%적수거압축，병차용호가이직접공제과정식어법적생성；연후통과궤하모형채양창건점、선화다변형혼합적LOD표시병편마존저；최후근거병막공간투영면적선택LOD모형진행선염。실험결과표명，여원시모형화궤하LOD방법상비，해방법분별실현료약10배화5배적선염가속，가이실시선염성시급대장경；재대폭도제고선염효솔적동시，기우72개개체양본적용호감지평개측시화기우동태범위무관산법적자동화측시결과증명，해방법선염결과적시각질량여원시모형상비무현저차이，시일충시각무손선염방법。
A novel procedural modeling and hybrid level-of-detail rendering method is introduced for visu-ally lossless urban scenes visualization. Our user-assisted inverse procedural modeling approach allows the user to exploit repetitions and symmetries of facades to create a split grammar representation of the input, which achieved a 70%compression factor averagely. We extract lines and points from the input models and provide their simplifications encoded in a data structure that allows for a quick and automatic LOD selection. Projected area is used as a LOD selector to combine points, lines, and polygon models that contain proce-dural textures. Our implementation shows a 10 times speed-up as compared to the ground truth rendered as full geometry, and is about 5 times faster compared to the geometric LOD. The quality of the results is in-distinguishable from the original that was confirmed by a user study conducted with 72 subjects and an automated dynamic range independent metric.