For more information about the metallic setup, you can refer to these links:
- Calibration chart: How to calibrate a metallic material (http://blogs.unity3d.com/wp-content/uploads/2014/11/UnityMetallicChart.png)
- Material chart: How to initialize the Standard Shader parameters for common materials (http://docs.unity3d.com/Manual/StandardShaderMaterialCharts.html)
- Quixel MEGASCANS: A vast library of materials, including textures and PBR parameters (https://megascans.se/)
- PBR Texture Conversion: How traditional shaders can be converted to PBR shaders (http://www.marmoset.co/toolbag/learn/pbr-conversion)
- Substance Designer: A node-based software to work with PBR (https://www.allegorithmic.com/products/substance-designer)
- The Theory of ...
