With each passing generation, technology enjoyers around the world breathlessly await the arrival of a new id Software game. While the id of today is far removed from its origins, the mission remains the same – to produce beautiful, state of the art visuals at blistering frame-rates. The studio’s latest work is no exception. Doom: The Dark Ages marks the arrival of id Tech 8 and with it, a massive slate of impressive tech arrives. From its reliance on ray tracing to its robust physics simulation and brand new materials system, all the through to massive scale battles boasting sublime physics and animation, this is a phenomenal technical showcase and a fantastic game.
One of the things I really appreciate about modern id Software games is the studio’s willingness to experiment and pivot. While the fundamentals of Doom: The Dark Ages are largely similar – shoot, pummel and otherwise vanquish demon hoards – the way in which this is achieved varies dramatically. Doom Eternal is a very different game compared to the 2016 reboot and this is also true of Doom: The Dark Ages, which shifts to much larger, open areas with higher enemy counts and very different mechanics. It is this desire to change the formula that helps drive the underlying technology. Fundamentally, id Tech 8 was designed to enable this particular game very specifically – which means it needed to support larger maps, more on-screen enemies and major changes to the way everything is lit.
When it comes to major changes from id Tech 7, the most impactful arguably stems from its shift to fully ray traced lighting, but beyond the obvious, ray tracing is used for other techniques and to improve the development experience. Similar to Indiana Jones and the Great Circle, the headline feature is ray traced global illumination. This allows for light sources to directly and indirectly light the surrounding space, creating beautiful, realistic and natural results. Unlike Eternal, The Dark Ages features a lot of soft lighting from the often dark skies above rather than high intensity electric lights everywhere.
Doom: The Dark Ages uses an irradiance cache in probe volumes. Before ray traced lighting like this, developers would often pre-calculate these results through pre-computing or ‘baking’. This technique meant that world lighting was more static and the actual iteration and build times were much slower. This is one of the most important shifts for the team. Speaking with Billy Khan, Director of Engine Technology at id Software, he noted that ray tracing essentially allowed them to shift to a What You See is What You Get model or WISIWYG. This means that when using id Studio, artists can adjust lighting directly in the editor and see the results instantly: something that would previously require baking to even preview, so it saves a lot of time, allowing the team to work at a much larger scale.