说明：  #使用内联节点引入米字造型，鼠标拖拽米字造型绕中心点任意旋转，无朝向限制。 #光线明暗变化动画。将黄色四边形平面的法向量由(0 0 1)变化为(0 1 1),再变化至(0 1 0),观察效果。
(# Inline nodes are used to introduce the meter-shaped shape. The mouse drags and pulls the meter-shaped shape around the center point arbitrarily, without direction restriction. # Light and shade change animation. The normal vectors of the Yellow quadrilateral plane were changed from (001) to (001) and then to (010) to observe the effect.)