I'm trying to draw an object in my near eye display and have it appear at the correct size at a distance. I can accomplish this if I'm looking at a wall in my office but not when I step outside. I'm an electrical engineer with only a cursory understanding of optics.
So I learned that if I want to draw an object, say a flat tree picture on a wall 10ft away then it is a simple ratio. Based on the eye relief (15mm in my case), and the size of the display and of the pixels. So if I draw my tree on my display and look at a wall 10ft away, everything is pretty close to the right size. As I back away it gets larger, and as I get closer it gets smaller. That makes sense.
Now if I step outside and look down the road my tree looks huge. How do I learn to draw objects appropriately so they appear the correct size here? Is there some maximum virtual screen size defined by my eye and the optics at infinity? I don't quite understand the concept or math I'd have to do for the scaling.