Hi. Tell me how to implement such a function. When you start the game, I determine the height and width of the screen and place the boards on the edge of the screen. Difficulty in determining the vec3 coordinates of the screen edges. How it can be implemented.
You can use the camera screen to world method to find world coordinates at a given screen coordinate, in front of the camera:
Search the forums as well, you can find several posts on the subject.