PhysicalMaterial is designed to accurately simulate real-world materials in a realistic and efficient shading model.
This mental ray shader is based on Maxwell’s material system and offers very few options compared to mental ray’s architectural materials by exposing only the most necessary shading parameters and internally adjusting others automatically in order to maintain physically plausible values:
- Reflection 0
- Reflection 90
- Index of refraction
- Roughness
- Bump
But even with these few options it is possible to create just about any (hard) surface material you could imagine, thanks to the shader’s built-in layering system. And since the shader is energy conserving it is really simple to create photorealistic shading, especially when used in combination with my PhysicalLight.
Of course it is also possible to get “under the hood” and tweak advanced features such as Final Gather contribution and ambient occlusion, but the shader is designed to let you ignore those for the most part… the presets pretty much simulate the material they say they will without much ado.
The shader features specular highlights based on Lafortune’s model, glossy reflections and an integrated layering system that lets you create iridescent coatings and advanced effects such as greasy specular highlights.
Usage
PhysicalMaterial is best suited for metals, plastics, car paint, clay, wood, stone… basically any type of hard material. The shader comes with a number of presets that simulate real world materials for quick setup in architectural renders.




