Unity 5.0.0f4

Developers still using this version often reference historical technical guides such as:

With 5.0.0f4, Unity introduced a unified Physically Based Shading system. This allowed materials to look consistent under different lighting conditions by simulating the real-world physical properties of light and surfaces. Metals looked like metal, and plastics looked like plastic, regardless of whether they were in a dark dungeon or bright sunlight. Real-Time Global Illumination with Enlighten unity 5.0.0f4

Warning: Do not download Unity 5.0.0f4 from third-party file repositories. The editor requires legitimate activation. and plastics looked like plastic