PreviewSurface: USD Workflows

The PreviewSurface node is a representation of the “USDPreviewSurface” shader which is meant to model a “modern” physically based surface with both specular and metalness workflows. PreviewSurface supports these either by enabling or disabling the Use Specular Workflow control. It has a variety of inputs such as roughness, specular, emission, diffuse, as well as hidden inputs for opacity, normals, AOVs, displacement.

Warning:  PreviewSurface node is still in Beta and may error when a texture input is connected. We suggest the use of the MtlXStandardSurface node.

In this example, we are using a PreviewSurface shader to add diffuse elements to an imported .usd prim.

1.

Import a .usd file into your scene with GeoImport. See Importing with GeoImport to learn more about this.

2.

Use a Read node to add your texture source image and connect it to the PreviewSurface node’s diff input.

3.

Connect the PreviewSurface shader node to the GeoBindMaterial’s mat input.

4.

Assemble the rest of your scene, for example with GeoScene and any lighting needed.

5.

Adjust the knobs to achieve your desired effect. For example, here we are turning up the Diffuse Color to achieve a brighter surface.

Note:  With the Use Specular Workflow checkbox turned off, increasing the Metallic knob can create a shiny metal look, preferred by games pipelines. For a similar effect for film pipelines, you may prefer turn the Use Specular Workflow checkbox on, and instead adjust Specular Color.