USD Preview Surface

The USD Preview Surface is a Mari shader designed to approximate the look of Pixar's UsdPreviewSurface. This shader can be used in tandem with Mari’s own Principled BRDF, or your own primary render vendor shader.

Note: This shader is only available for versions of Mari 4.8 and later.

Inputs

Control	Type	What it does	Dialog	Notes
	toggle	Toggles the influence of channels connected to the shader without disconnecting them from the shader input.
	button	Adds a new channel for the shader component.	Add Channels Dialog
Diffuse Color	dropdown	The channel controlling the overall diffuse color of the shaded surface.
Emissive Color	dropdown	The channel controlling the color of the emissive (glow) qualities on the shaded surface.
Use Specular Workflow	dropdown	Enables or disables use of the Specular Color and Metallic channels to drive an asset’s reflective properties using maps connected to the channels.
Specular Color	dropdown	The channel controlling specular color on the shaded surface. When Use Specular Workflow is enabled, you can connect a specular map to drive an asset’s reflective properties.
Metallic	dropdown	The channel specifying the areas on the material that have a metallic effect. When Use Specular Workflow is enabled, you can connect a metallic map to drive an asset’s reflective properties.
Roughness	dropdown	The channel controlling how rough the material is. Rough materials scatter reflected light in more directions than smooth materials.
Clearcoat	dropdown	Specifies the strength of clearcoat properties applied to the shaded surface.
Clearcoat Roughness	dropdown	Specifies the strength of clearcoat roughness properties applied to the shaded surface.
Opacity	dropdown	Controls the opacity strength of the shader.
Opacity Threshold	dropdown	A clamping feature that reverts opacity to 0 when the opacity slider is set below the specified threshold amount.
Index of Refraction	dropdown	Specifies the strength of IOR properties applied to the shaded surface.
Normal	dropdown	The channel containing the Normal map, used to give additional physical details to a surface.
Occlusion	dropdown	The channel used to specify the self-shadowing that occurs on an occluded object.
Bump	dropdown	The channel controlling the bump map effect of the shaded surface.
	button	Inverts the channel values of the selected channel.
Vector	dropdown	The channel controlling the vector field and resulting vector data from paint on the shaded surface.		This data is used by the vector inspector.
Displacement	dropdown	The channel controlling the displacement map effect of the shaded surface.		Displacement Map is toggled off by default.

Shader

Control	Type	What it does	Notes
Diffuse Color	swatch	Sets the Diffuse Color.
/	toggle	Whether this channel is color or scalar data.	See Color Data and Scalar Data for more information.
	button	Resets a control back to its default value.
Emissive Color	swatch	Sets the Emissive Color.
/	toggle	Whether this channel is color or scalar data.
Use Specular Workflow	checkbox	Enables or disables use of the Specular Color and Metallic channels to drive an asset’s reflective properties using maps connected to the channels.	Use Specular Workflow is disabled by default.
Specular Color	swatch	Sets the Specular Color. When Use Specular Workflow is enabled, you can connect a specular map to drive an asset’s reflective properties.	Specular can use a full range of gray scale values from 0-1.
/	toggle	Whether this channel is color or scalar data.
Metallic	slider	Sets the Metallic color. When Use Specular Workflow is enabled, you can connect a metallic map to drive an asset’s reflective properties.	Metallic only supports value 0, not metal, and 1 metal, though the control is a slider.
Roughness	slider	Controls how rough the material is. Rough materials scatter reflected light in more directions than smooth materials.
Clearcoat	slider	Specifies the strength of clearcoat applied to the shaded surface.
Clearcoat Roughness	slider	Specifies the strength of clearcoat roughness applied to the shaded surface.
Opacity	slider	Controls the opacity strength of the shader.
Opacity Threshold	slider	A clamping feature that reverts opacity to 0 when the opacity slider is set below the specified threshold amount.
Index of Refraction	slider	Specifies the strength of IOR properties applied to the shaded surface.
Occlusion	slider	Specify the amount of self-shadowing that occurs on an occluded object.
Mari Only
Transparency to Environment	checkbox	When enabled, attempt to fake transparency by rendering the environment behind objects.	Works best in Perspective camera mode.

Mari Surface

Note: Mari Surface is an approximation and may not accurately reflect the same settings in the renderer you're currently using.

Control	Type	What it does	Notes
Bump
	button	Resets a control back to its default value.
Bump Weight	text field, slider	How much weight the bump map has. Lower values are smaller bumps, higher values are larger and more obvious displacements.	From 0 to 10, defaults to 0.1.
Bump Mode	dropdown	Displays bump quickly (Fast), accurately (Accurate), or less accurately (Fastest).	While Fastest is very fast, it works better with live procedural layers rather than painted or cached layers.
Bump Space	dropdown	• UV - Normals are calculated relative to the UV coordinates space. UV mode is the more traditional approach but can lead to noticeable seams and color variations. • World - Normals are calculated relative to the World coordinates space. Using World mode produces a more seamless result.	By default, Bump Space is set to UV.
Displacement
Displacement Bias	text field, slider	How much the white or black values are pushed or pulled from the surface.	From 0 to 1, defaults to 0.5.
Displacement Scale	text field, slider	How much displacement is applied to the shaded surface. Lower values equal smaller displacement and higher values equal larger and more obvious displacement.	From 0 to 1, defaults to 0.5.
Displacement Range	text field	Sets the range of displacement. This setting is multiplied by the Displacement Scale to give the displacement.
Max Tesselation	text field, slider	The surface is tessellated to a maximum of this number of texels.	From 1 to 64, defaults to 10.
Perturb Normals	dropdown	Selecting Yes causes displacement to move the surface, but leave the surface normals as they are.