中文摘要：

定量视域分析是应用空间句法理论研究城市规划和建筑物布局合理性的基础．提出了一种定量视域分析算法，从视点每隔一定角度发出一条射线与建筑物实体或区域边界相交，选取每条射线上距离视点最近的交点构造视域多边形，通过消除共线冗余点优化视域多边形，并据此计算出面积、周长、形心和闭塞度等视域属性变量．实验结果表明，该方法获得的视域属性变量能较好的反映出空间的视觉特性，具有较强的应用价值．

英文摘要：

The analysis of quantitative visibility is the basis for studying urban planning and reasonable layout of the build- ing in the application of space syntax. An algorithm for analysis of quantitative visibility is proposed in the paper. Firstly, the rays are given off from every angle of the viewpoint to intersect with the building physical border or the region border, and then the visibility polygons are constructed by using the points of intersection which are nearest to the viewpoint on each ray and optimized by eliminating redundant collinear points. Finally, such attribute variables of the visibility poly- gons are calculated, as the area, circumference, centroid and occlusivity. Experimental results show that the algorithm can be used to obtain attribute variables which have a better reflect of the spatial visibility characteristics, and it has a bet- ter practical value.