That indicates the type of the connection point. 指示连接点类型的。
"absolute principle, top priority" 硬道理
In the arbitrary based polygonization, rendering of arbitrary point sets joins the points to form a closed mesh on the skin of a shape represented by the points. 在任意基准多边化中,可以将任意点移动到接合点以形成由这些点构成的外部形状封闭的网格。