The problem is the way surface lighting/scattering is calculated, which does not match what traditional offline renders do. My issue with UE is the opposite, t

The problem is the way surface lighting/scattering is calculated, which does not match what traditional offline renders do. My issue with UE is the opposite, the engine went too far into cinema production, and making it a performant game engine requires code refactoring. At which point an open-source engine might be a better choice. Its a mix of two (three) worlds, and not the best choice for one specific use. For what is actually hard to do, like character animation, UE is a good choice. The lighting can be replaced more easily than the animation system.