title: How to calculate a pixels world space position on an image plane formed by a virtual camera?
body: <p>First, this <a href="https://stackoverflow.com/questions/14094042/calculating-camera-ray-direction-to-3d-world-pixel">Calculating camera ray direction to 3d world pixel</a> helped me a bit in understanding what the virtual camera setup is like. I don't understand how the vectors work in this setup, and I thought normalized device coordinates had to be used which led me to this page <a href="http://www.scratchapixel.com/lessons/3d-basic-lessons/lesson-6-rays-cameras-and-images/building-primary-rays-and-rendering-an-image/" rel="nofollow noreferrer">http://www.scratchapixel.com/lessons/3d-basic-lessons/lesson-6-rays-cameras-and-images/building-primary-rays-and-rendering-an-image/</a>. What I am trying to do is build a ray tracer, and as the question states, find out the pixels position in order to shoot out a ray. What I really, really really would like, is an actually  example showing a virtual camera setup, screen resolution and how to calculate a pixels position, then transform to world space coordinates. Experts!, Thank you for your help! :D</p>