| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To speed up hidden line elimination that inhibits representation of a line segment hidden in a polygon, and significantly reduces the time for processing. <P>SOLUTION: The invention is a hidden line elimination method which performs processing of preventing projection of a line segment hidden in the polygon at projecting of a three-dimensional model, consisting of a plurality of polygons on a two-dimensional plane surface. A maximum value PZ<SB>max</SB>of the Z-axis direction element of each vertex in a visual point coordinate system is obtained for each of the plurality of polygons, belonging to arbitrary parts that constitute the three-dimensional model. The plurality of polygons are sorted in a descending order by the maximum value PZ<SB>max</SB>. A value LZ<SB>min</SB>, which is smaller in the Z-axis direction element, in the visual point coordinate system of the two end-points of the arbitrary line segments obtained from the plurality of polygons, is calculated. Comparison is made between the smaller value LZ<SB>min</SB>in the Z-axis direction element of the arbitrary line segments and the maximum value PZ<SB>max</SB>of the Z-axis direction element of the plurality of polygons in the sorted order, and in the case of LZ<SB>min≥</SB>PZ<SB>max</SB>, determination as to whether the line segments are hidden lines is omitted for the polygon after the plurality of the sorted polygons. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
