I'm sure there are whole pages about this somewhere, but I'm not sure what I'm looking for.
How would I do a basic fake 3d image of an object, if I'm looking out of the player's eyes and I know the location of the object in relation to the player, and the angle the player is looking? I'm aware that the image of the object would be very difficult to implement in 2d this way, but let's assume the object is always looking directly at the player and it's shape is unimportant. All I need to know is, how can I work out where it would be placed on the screen when looking from the players eyes?
To make this a bit clearer, let's say the player is looking straight ahead, the object is 10 feet ahead and 10 feet to the right (so 45 degrees ahead of him) and the players eyes are always 5 feet from the ground. How would that convert to 2d coordinates and scale?