Research of Isoline Rendering Based on 3 -Subdivision

The TIN automatic created is a important link in the process of draw contour, however when the distance of measuring points are farther, and the laxity of measuring matrix is bigger different, the structure of Delaunay triangle is often bigger in the measuring point sparse area, which caused the contour precision not to be high. Therefore, this article firstly analyses TIN automatic created, withdraws the sparse network region from TIN, then introduced radic3-subdivision algorithm, and refines the Delaunay triangle in this region, thus has formed a finer TIN, enhanced the expression of measure data to the entity, and increased the contour algorithm precision