This is part 1 of the “How Unreal Renders a Frame” series, you can access part 2 and part 3 as well.

I was looking around the Unreal source the other day and inspired by some excellent breakdowns of how popular games render a frame, I thought to try something similar with it as well, to study how it renders a frame (with the default settings/scene setup).

This is Part 1 of a series examining techniques used in game graphics and how those techniques fail to deliver a visually appealing end result. See Part… for a more thorough explanation of the idea behind it.

High dynamic range. First experienced by most consumers in late 2005, with Valve’s Half Life 2: Lost Coast demo. Largely faked at the time due to technical limitations, but it laid the groundwork for something we take for granted in nearly every blockbuster title. The contemporaneous reviews were nothing short of gushing. We’ve been busy making a complete god awful mess of it ever since.

Let’s review, very quickly. In the real world, the total contrast ratio between the brightest highlights and darkest shadows during a sunny day is on the order of 1,000,000:1. We would need 20 bits of just luminance to represent those illumination ranges, before even including color in the…