The type of the material used to render a terrain object. Could be one of the built-in types or custom.
| BuiltInStandard | A built-in material that uses the standard physically-based lighting model. Inputs supported: smoothness, metallic / specular, normal. |
| BuiltInLegacyDiffuse | A built-in material that uses the legacy Lambert (diffuse) lighting model and has optional normal map support. |
| BuiltInLegacySpecular | A built-in material that uses the legacy BlinnPhong (specular) lighting model and has optional normal map support. |
| Custom | Use a custom material given by Terrain.materialTemplate. |