# Preview Surface A MaterialX version of USD Preview Surface. ## Parameter Types |Input |Type | |---------------------|-------------| |`Diffuse Color` |Color3| |`Roughness` |Float | |`Metallic` |Float | |`Opacity` |Float | |`Normal` |Vector3f | |`Clearcoat` |Float | |`Clearcoat Roughness`|Float | |`Emissive Color` |Color3| |`Index of Refraction`|Float | |`Ambient Occlusion` |Float | |`Opacity Threshold` |Float | |Output|Type | |------|-----| |`Out` |Token| ## Parameter description - `Diffuse Color`: The base display color of the surface. The color of an object under pure white light. - `Roughness`: The level of roughness of the surface. This value ranges between `0` and `1.0`, with `0` outputting a perfectly specular surface and `1.0` indicating maximum roughness. The default is `0.5`. - `Metallic`: The indicator if a surface is metallic or not. Set this value to `1` for metallic surfaces and `0` for nonmetallic surfaces. The default is `0.0`. - `Opacity`: The level of opaqueness of the surface. If the value of this parameter is `1.0`, the surface is fully opaque. If the value is less than `1.0`, the surface appears translucent. If the value is `0`, the surface is completely transparent. The default is `1.0`. - `Normal`: The normal vector in tangent space; the default is `(0,0,1)`. - `Clearcoat`: A second clear reflective layer on the surface. This property produces a glossy finish. The default is `0.0`. - `Clearcoat Roughness`: The level of roughness of the surfaces clearcoat layer; the default is `0.01`. - `Emissive Color`: The self-illumination color of the surface. The color the surface displays as if it is self-lit. - `Index of Refraction`: The index of refraction the node uses if the surface is translucent or specular. The `Index of Refraction` defines how light bends or refracts when it passes through a material. The default is `1.5`. - `Ambient Occlusion`: The degree of ambient lighting that the surface receives. This value simulates soft shadows and subtle shading. A value of `0.0` indicates a fully occluded area, while a value of `1.0` indicates an unoccluded area. The default is `1.0`. - `Opacity Threshold`: The threshold for whether the node renders a portion of the surface based on its opacity level. A value of `0.0` means that no additional masking occurs. If the value is greater than `0.0`, the node renders only areas of the surface with an `Opacity` value greater than the value of this parameter. The default is `0.0`. ## Discussion The `Preview Surface` node produces a custom surface based on its input parameters. Connect the output of the `Preview Surface` node to the `Custom Surface` output of your material. Below is an example material that uses only the `Preview Surface` node to produce a gold-like texture and apply it to a sphere:   --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)