Tech Interview: Split/Second

Pure's engine is based on a core set of libraries called Blimey that have been in development at our studio for the past 10 years. They provide all the basic building blocks for making a game, such as maths functions, serialisation, memory and file management and so on.

The original Blimey libraries had a PS2 and Xbox renderer and then in 2003 our Core Technology Group (CTG) started work on a next generation renderer on the PC. That renderer is still in use today in our in-house modeling tool called Tomcat. In January 2005 we began the work of porting the renderer to the Xbox 360 ready for our first next-gen title MotoGP '06. It was a good renderer, if a little feature-light by today's standards, and it had a solid lighting model at its core.

When the Pure team started up the following year they took the renderer used by MotoGP '06 and extended it greatly, particularly making advances in post-processing such as motion blur, colour grading, vignetting and bloom. For Split/Second we took the Pure renderer and used that as the starting point for the Split/Second renderer.

I think the key in dealing with the differences between Xbox360 and PS3 is having a deep understanding of the hardware for both. If you really want to push both consoles to their limits then you need specialised code paths for each platform.

On the Xbox 360 it's all about leveraging the powerful GPU and on the PS3 it's all about SPU utilisation - these are fundamentally different technologies that require very specific code paths. On Split/Second, the final image for each platform is nearly identical but how the pixels get into the image is very different indeed.

Pure had to render a massive amount of alpha-heavy foliage which just wouldn't have been possible using traditional techniques. We came up with some innovative new ways of rendering alpha - for more information check out our technology page.

Pure is our biggest-selling title to date and thanks to a Microsoft bundle deal has reached millions of users. It was the title that established us as a AAA games studio and whenever we speak to people about Split/Second they recognise Black Rock from Pure - it was a great expression of intent for the studio.

The Pure engine was very well suited to the requirements of Pure and so the overhaul required was due to the differing requirements of Split/Second rather than any deficiencies in the engine. We rewrote the render engine to be a gamma correct deferred shading renderer rather than a more traditional forward renderer.

We placed a lot of emphasis on further improvements to the post-processing pipeline with per-pixel motion blur and anamorphic lens flare. We also introduced a colour grading system whereby the artists could take a screenshot and bring it into Photoshop and then treat the image however they liked. We have some software that analyses the colour mappings that the artists had performed and recreated them in the game. This system is used at all times during gameplay to give the exact look we want.

We also invested a lot in a new VFX pipeline for the huge volumes of dust, smoke and fire in the game. There's a lot of processor power that goes into the VFX and a lot of clever tricks to be able to render huge amounts of them without exceeding the fill-rate. The particles are all correctly lit from the light sources and the smoke even moves out of the way as the vehicles travel through it.

I don't think so - the Burnout boys all love arcade racers and what attracted them to Split/Second was the opportunity to put a new twist on the genre they love. Right from the beginning Split/Second was its own game and the similarities with Burnout are fairly superficial.