Material shaders control how surfaces look when rendered. Materials are digital assets, containing the shader’s definition in VOPs, and a parameter user interface. Users can instantiate multiple copies of a material and use the material’s parameter interface to edit them. For example, you could create two copies of a Brick material asset, and change each copy’s Color parameter to create a red brick and a yellow brick material.

You can create your own material assets using a network of VOP nodes, and promote parameters on the VOP nodes up to create the user interface of the material asset. For information on how to build your own materials using a VOP network, see building materials.

• Houdini includes several useful built-in materials on the material palette.

• The Principled Shader material is a “physically plausible” “über-shader” that lets you create almost any look using a small set of intuitive artistic controls.

• Specialized materials are available for other types of materials such as Skin and Glass.

• You can layer existing materials to create more complex looks, for example scratches and rust over a metal base.

• You can get practically any realistic look using the Principled material or other built-in materials, possibly with layering. However, if you need something non-realistic or custom, you can build your own shader.

  

• Mantra ships with two “über-shaders”, Principled Shader and Classic Shader (formerly known as the Mantra Surface shader). We recommend using the Principled Shader unless you need one of the specialized features on the Classic Shader: more control over sub-surface scattering, and/or control over refraction roughness separate from reflection roughness.

Houdini comes with a wide array of pre-made materials in the material gallery. The material palette lets you assign and customize materials from the gallery.