Why the Unreal engine instead of Quake 2?
According to 3D Realms it was a business decision based on where they were in the game’s development. One big factor was that 3D Realms wanted to do vast outdoor areas, such as the Hoover Dam, which the Unreal engine is much better at than the Quake 2 engine. The Unreal engine also has a much better tool set which should speed up development time in the long run. Many of the features that 3D Realms was adding to the Quake 2 engine, such as procedural water, are already in the Unreal engine, which means they don’t have to spend time developing and testing them. Another factor is that when Duke 4 was using the Quake 2 engine, the game was going to be hardware-only, because writing a 16-bit software renderer would have been too time-consuming. The Unreal engine, however, already has a very good software renderer, so the game will no longer be hardware-only.
