) When licensing the Far Cry brand you purchased the Cry Engine and it seems logical that this powerful peace of technology will be the technical base of Far Cry 2 too? Is that correct?
DG: No, I understand the reasoning but it is incorrect. The engine was licensed mostly for use on the console adaptations of the original Far Cry. On Far Cry 2, we had a mandate not only to build an ambitious sequel to Far Cry but also to build a new cutting edge in-house technology. We started building that new technology in 2005. Our engine is called Dunia and was built from the ground up to support the scope and goals of Far Cry 2.
2) Was it necessary to reprogram or even add code to the engine? If so what parts were altered what kind of technical features were integrated into the engine? What were the reasons behind these alterations?
DG: Well, Dunia was built from the ground up. It was developed during the last 3 years in our R&D effort for Far Cry 2. We had a few major goals in mind as we built the technology. First, we wanted to get rid of the concept of "levels". "Levels" have been used since before the Pac Man days to manage progression and content and are, from a technical standpoint, a very safe way of managing things. However, FC2 is a truly open world game and we couldn't do with such a limitation anymore. A change of scale like that one changes a lot of thing in a technology.
Also, we wanted to have a very dynamic game environment. We worked hard on physics simulation systems and enabling a lot of destructibility and interactivity. This also includes an arbitrarily destructible and physically simulated vegetation system codenamed RealTree. Also, we wanted to make sure our graphic technologies permitted a very high quality recreation of a realistic Africa with a real-time 24 hours day-night cycle.
Finally, another big focus from the beginning was the online. We wanted to have excellent online technology: not just quality net code but also things like matchmaking services and map editing.
3) In general what according to your personal experience makes the Cry Engine so special for the development of Fps games? Why do you decide against developing a new engine from scratch for Far Cry 2?
DG: Well...we did make a new engine. ï Cry Engine had some strong qualities but it was suited for another generation of hardware.
4) One part of the Cry Engine is a very powerful renderer that guaranties a very modern visual presentation including rendering techniques like Parallax Mapping, Soft Shadows, a HDR lighting model. Besides this are there other graphical highlights that require a revision of the code? If yes could you please give examples and explain in technical terms how this new visual features are realized?
DG: Dunia supports all those graphical features and many more. One big evolution that we brought to our graphic technology is the fact that our lighting model is completely dynamic, including the sun. That means that the sun can move in realtime during game time and the whole scenes lighting adapts accordingly. Also of note, we implemented a dynamic ambient lighting algorithms that manage the radiosity component of the lighting in the environment: basically what is also referred to as "indirect lighting".
Another feature I like a lot is our procedural sky rendering system. We can basically manipulate the meteo according to our wish and the sky adapts in real time.
5) First impressions of the game show that Far Cry 2 will offer a dynamic day and night cycle as well as a very detailed weather simulation? Were you able to realize this with the original version of the engine/renderer? Could you please give technical details how they are rendered? What makes them so special compared to other titles of the genre?
DG: Games have simulated weather changes for a long time. However, to be able to see the clouds gather in the sky gradually, to see the trees bending more and more with the force of the wind, to see the grass folded by the gusts of wind, we had to develop a few key technologies. Key among those is the RealTree system. This technology let's us move away from having the typical very limited physical reactions of the vegetation to wind to a much higher quality physical simulation. So it's one thing to have the "weather system" feature, what we wanted to do was push the simulation, push the immersion and push the gameplay potential of the idea further.
Likewise for the dynamic time of day. Many games have had dynamic time of days and that for quite some time. However, most would bake discreet time of days and shift between them or just compromise the graphic quality to get the feature in. We didn't want to do either one of those things. So we needed all of our lighting features to be fully dynamic and that was an interesting challenge. ï