project marker corners to screenspace

Unity Engine
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1

Hello!

I’m trying to project the corners of a marker into the screen. The code below is working fine with a mockup scene without AR in the editor but it does’t work on device. Am I missing something really basic here?

var m = Matrix4x4.TRS(MarkerTransform.position, MarkerTransform.rotation, Vector3.one);

var upperLeft = ARCamera.WorldToScreenPoint( m.MultiplyPoint(new Vector3(-hWidth,0,  hHeight)));
var upperRight = ARCamera.WorldToScreenPoint(m.MultiplyPoint(new Vector3(hWidth,  0, hHeight)));
var lowerRight = ARCamera.WorldToScreenPoint(m.MultiplyPoint(new Vector3(hWidth, 0,-hHeight)));
var lowerLeft = ARCamera.WorldToScreenPoint(m.MultiplyPoint(new Vector3(-hWidth,  0,-hHeight)));

Thanks so much for any pointers!

seb

2

Could you provide more info as to what isn’t working?
My first guess would be that your ARCamera isn’t updated with the proper matrix yet.
Check the ARCameraBackground.OnCameraFrameReceived-Method. This is where the Projection-Matrix from the Device-Camera is set to your ARCamera. Your code should run after this function.
Thus, you’ll want your code to run after the ARCameraManager.frameReceived-Event, either by adding your own listener to that event, or by running your code in LateUpdate (the event is fired from Update)

3

Hi. Any success with this?