Screen.perspectiveOriginY < number>

Sets the y origin for 3D transformations. The origin is defined as a number, where 0 is the top edge of the screen and 1 the bottom edge. The default value is 0.5, the center of the screen.
译：设置三维转换的Y原点。的起源被定义为一个数字，其中0是屏幕的顶部边缘和1的底部边缘。默认值为0.5，屏幕的中心。

# Rotate layer in 3D 
layerA = new Layer
    rotationX = 30

# Set vertical perspective origin 
Screen.perspectiveOriginY = 1