: Shadow of Chernobyl, notably Oles Shishkovtsov and Oleksandr Maksimchuk, the programmers who worked on the development of the X-Ray engine used in the S.T.A.L.K.E.R.

[2] Shishkovtsov and his colleagues split from the development of S.T.A.L.K.E.R because that "its inherent inability to be multi-threaded, the weak and error-prone networking model, and simply awful resource and memory management which prohibited any kind of streaming or simply keeping the working set small enough for 'next-gen' consoles" along with its "terrible text-based scripting", which he explained led to the delays in the original game.

Shishkovtsov also said that the GeForce 6 series architecture of the RSX Reality Synthesizer in the PlayStation 3 proved to be very useful during development noted that there were many "wasted cycles".

[3] The 4A Engine implementation of Metro 2033 features volumetric fog, double PhysX precision, object blur, sub-surface scattering for skin shaders, parallax mapping on all surfaces and greater geometric detail with a less aggressive LOD(s).

Using PhysX, the engine uses many features such as destructible environments, and cloth and water simulations, and particles that can be fully affected by environmental factors.