About Hidden line removal

Hidden line removal











        Hidden line removal is an extension of wireframe rendering where lines (or segments of lines) covered by surfaces are not drawn.

        線消隱是一個擴展的線框渲染下線（或部分行）由平面並非曲面。




        This is not the same as hidden face removal since this involves depth and occlusion while the other involves normals.

        這是和隱藏面(hidden face removal)不一樣的因為這涉及的深度和閉塞，而其他涉及法線。 



        A commonly used algorithm to implement it is Arthur Appel's algorithm (Appel, A., "The Notion of Quantitative Invisibility and the Machine Rendering of Solids," Proceedings ACM National Conference, Thompson Books, Washington, DC, 1967, pp. 387-393.). This algorithms works by propagating the visibility from a segment with a known visibility to a segment whose visibility is yet to be determined. Certain pathological cases exist that can make this algorithm difficult to implement. Those cases are (i) vertices on edges and (ii) edges on vertices and (iii) edges on edges. This algorithm is unstable because an error in visibility will be propagated to subsequent nodes (although there are ways to compensate for this problem). Also see James Blinn's "Fractional Invisibility," IEEE Computer Graphics and Applications, Nov. 1988, pp. 77-84.

       一個常用的算法實現，是亞瑟阿佩爾的算法（阿佩爾，答：“定量的概念和隱形機呈現固體，”訴訟ACM全國會議，湯普森書籍，華盛頓特區，1967年，頁。 387-393 。）。這種算法的作品傳播的能見度從部分與已知的能見度一個分部，其能見度尚未確定。存在的某些病理情況下，可以使該算法難以實施。這些案件是：（一）頂 點的邊和（二）邊的頂點，（三）邊緣的邊緣。該算法是不穩定的，因為一個錯誤的能見度會傳播到後續節點（雖然有一些方法可以彌補這個問題）。也看到詹姆斯 Blinn的“隱形分數，”IEEE計算機圖形與應用，1988年11月，頁。 77-84。