Ascertaining real touch position
What I want to do is locate a touch position in a scene.
The problem is that touch, mouse position, and raw mouse position all give me coordinates for the screen position, not the actual position.
Example: A scene is 5000x5000 pixels. The screen size is 1024x768, and the camera is centered on 2500x2500. If I touch directly in the middle of 2500x2500, it will give me the coordinates 512x384 instead of 2500x2500.
How does one ascertain the real touch position? Why are there three different ways to ascertain pointer positions, yet none of them gives the actual real touch position?