Convert Scene's (x, y) to screen's (x, y)

问题

I have an application built with SceneKit that is currently displaying several nodes. I can figure out which node is pressed and want to use that to make a label appear below the Node that was touched. Now, when I set the label's center the following way...

nameLabel.center = CGPointMake(CGFloat(result.node.position.x), CGFloat(result.node.position.y+20)

…it appears in the upper left corner since the node is on (1, 0). What I figured is that the sceneView's (0, 0) is in the center of the screen while the actual physical display's (0, 0) is in the top left corner.

Is there a way to convert the two different numbers into each other? (I could hardcode since I know where the Node's are or create a separate label for each Node but that is not really a perfect solution.)

Thanks in advance :)

回答1:

You can use the projectPoint: method:

var projected = view.projectPoint(result.node.position))   
//projected is an SCNVector3
//projected.x and y are the node's position in screen coordinates
//projected.z is its depth relative to the near and far clipping planes
nameLabel.center = CGPointMake(CGFloat(projected.x), CGFloat(projected.y+20)

来源：https://stackoverflow.com/questions/29687989/convert-scenes-x-y-to-screens-x-y