Abstract:

In the three-dimensional virtual battlefield, due to the influence of the curvature of the earth and the relief of the terrain, the connection straightlines between military targets will appear as a phenomenon of “piercing mountains”. Aiming at this problem, combined with the aesthetic principle of network visualization, a convexity visualization algorithm for military target relationship is proposed. Firstly, the profile analysis is performed between the targets to obtain the elevation sampling data set. Secondly, the strategy of fusion and replacement with targets is proposed using the Graham convex hull algorithm, to obtain the set of convex feature points reflecting the overall trend of the terrain. Finally, the geometric construction method of the Bézier curve control points for convexity preservation is proposed, and the segment-by-segment smooth interpolation is performed. It achieves the convexity visualization of the entire curve. The experimental results show that it eliminates a phenomenon of “piercing mountains”, and has a fine visual aesthetic feeling： fitting the terrain, keeping convexity, and smoothing the whole curve.

Key words: virtual battlefield, network visualization, terrain fitting, terrain sampling, convex hull, convex-preserving, Bézier curve control points

摘要：

在三维虚拟战场中，由于地球曲率及地形起伏的影响，军事目标之间的连线会出现“穿山入地”现象。针对该问题，结合网络可视化美学原则，提出了一个军事目标关系的保凸可视化算法。在目标之间进行剖面分析，获取表达地形起伏的高程采样数据；提出了与目标等的融合、替换及剔除策略，基于Graham凸包算法，优选出反映地形整体变化趋势的保凸特征点集；提出了保凸的贝塞尔（Bézier）曲线控制点的几何构造方法，通过逐段光滑插值，实现了整条曲线的保凸可视化。实验结果表明：消除了目标连接直线“穿山入地”的现象，具有较好的视觉美感：拟合地势、整体保凸、整体光滑。

关键词: 虚拟战场, 网络可视化, 拟合地势, 高程采样, 凸包, 保凸, 贝塞尔曲线控制点