Materials

Materials control the appearance of 3D objects in a scene. Within Autograph, you can:

Create new materials to use with 3D objects
Assign materials to 3D objects
Override an existing material

Creating a material

To create a new material, go to the Outliner panel, and in the Add menu choose Material.

New material

A new primitive of type Material is created. Select it to display its properties in the properties panel.

Assigning a material to an object

After creating a material, you need to assign it to one or more objects in your scene. To assign a material to an object, (1) select the object in the Outliner and (2) go to the Materials panel. (3) Using the drop-down, pick a material from the list of available materials in the scene. Your material is now assigned to an object and should be visible in the viewport.

Assign material

Note

Do not forget to add a Light to your scene, otherwise non-emissive materials will appear black.

Overriding a material

Danger

Currently, overriding a material loaded from an existing USD asset will reset its properties to default values (including any references to texture maps). This is a limitation of the current system.

To override an existing material primitive, (1) navigate to the material in the Outliner and (2) click the Edit primitive button on the panel below.

Override material

The overriden material's properties are now displayed.

Material properties

Autograph has two rendering backends (render delegates): Storm, part of the USD/Hydra project, and Filament, a real-time physically based rendering engine. Each has different rendering capabilities and material models. Autograph offers a unified material model, allowing you to specify your material once and have it work with both renderers.

Under the hood, the parameters of this unified model are translated to delegate-specific material models:

for Storm, material properties are translated to the corresponding UsdPreviewSurface input, when such an input exists.
for Filament, material properties are translated to the Lit and Unlit models provided by Filament.

Texture Maps

Some material properties have an associated Map parameter, which can be connected to a texture map in order to make the value vary over the surface of the object. Map parameters are regular image parameters, meaning that anything you would use as layer source could also be used as an animated texture map on a 3D object. This includes:

Video sources
Generators
Whole sub-compositions

Modifiers are also supported on texture maps.

Generators as texture maps

When binding a generator to a texture map parameter, make sure that the Output Format of the generator is not Unbounded, otherwise rendering will fail.

Tangent-space normal maps

Normal maps should be specified in tangent space. We use MikkTSpace internally to generate a standard tangent space when tangents are not explicitly specified on a USD primitive.

List of material properties

Some parameters are only supported by a specific render delegate, this is indicated below in the "Supported Delegates" column.

Note

Some material properties have both a numeric input and a texture map input (e.g. Base Color and Base Color Map). The texture map input, if it is connected, takes precedence over the numeric input.

Parameter	Description	Supported Delegates
Shading Mode	Selects the overall shading model of the material None: unlit model, the material appearance is unaffected by lighting Normal: generic physically-based shading model	Filament only (only Normal model supported on Storm)
Blending Mode	How the material blends with the rest of the scene. See the dedicated section below.	Filament only
Mask Threshold	Alpha value threshold for the Alpha Masked blending mode.	All
Base Color Base Color Map	Base color (diffuse albedo or specular color for Metallic materials). Storm: maps to diffuseColor Filament: maps to baseColor	All
Opacity Opacity Map	The opacity of the material.	Filament only
Metallic Metallic Map	Binary value specifying whether the material is metallic or not.	Filament only
Roughness Roughness Map	Controls the perceived smoothness of the surface. See Roughness	Filament only
Reflectance Reflectance Map	For non-metallic materials, control the specular intensity and index of refraction of materials. Reflectance	Filament only
Sheen Color Sheen Color Map	Controls the appearance the sheen layer, above the base layer and below the clear coat. See Sheen color	Filament only
Sheen Roughness Sheen Roughness Map	Roughness of the sheen layer. See Sheen roughness	Filament only
Clearcoat Clearcoat Map	Strength of the clear coat layer. See Clear coat	Filament only
Clearcoat Roughness Clearcoat Roughness Map	Roughness of the clear coat layer. See Clear coat roughness	Filament only
Normal Map	Defines the normal at a point on the surface. See Normal.	All
Bent-Normal Map	Defines the average unoccluded direction at a point on the surface. See Bent normal.	Filament only
Clearcoat Normal Map	Defines the normal used for the clear coat layer at a point on the surface. See Clear coat normal.	Filament only
Anisotropy	Enables anisotropic highlights. See Anisotropy.	Filament only
Anisotropy Direction	Controls the direction of anisotropic highlights. See Anisotropy direction.	Filament only
Ambient Occlusion Ambient Occlusion Map	Defines how much of the ambient light is accessible to a surface point. See Ambient occlusion.	All
Emissive Emissive Map	Emissive component of the material.	All
UVs name	Name of the texcoord primvar to use on the primitive.	All
Wrap S	Wrapping mode of the S texture coordinate.	All
Wrap T	Wrapping mode of the T texture coordinate.	All
Specular Ambient Occlusion Mode	See Lighting: specularAmbientOcclusion	Filament
Refraction Mode	Controls the refraction effect. None: disable refraction. Screen-space: screen-space refraction. See Blending and transparency: refractionMode	Filament
Refraction Type	Defines the refraction model used. See Blending and transparency: refractionType	Filament
Reflection Mode	Controls the source of specular reflections. Environment-Only: only light from environment lighting (dome lights) is reflected. Screen-space: enable screen-space ray-marched reflections. See Lighting: reflections	Filament
Transparency Mode	Controls how transparent objects are rendered. See Blending and transparency: transparency	Filament
Transparent Shadows	Enables shadows on transparent objects. See Lighting: transparentShadow	Filament
Specular Anti-Aliasing	Enables aliasing reduction on specular highlights. See Anti-aliasing: specularAntiAliasing	Filament
Specular Anti-Aliasing Variance	See Anti-aliasing: specularAntiAliasingVariance	Filament
Specular Anti-Aliasing Threshold	See Anti-aliasing: specularAntiAliasingThreshold	Filament
Clearcoat IOR Change	Enables attenuation of the base layer due to the change in index of refraction in the clear coat layer. See Lighting: clearCoatIorChange	Filament
Multi-Bounce Ambient Occlusion	See Lighting: multiBounceAmbientOcclusion	Filament

Blending mode

With the Filament render delegate, the Blending mode options controls how the material blends with the rest of the scene:

Blending mode	Description
Opaque	Blending is disabled, the alpha channel of the material's output is ignored.
Transparent	Blending is enabled. The material's output is alpha composited with the background. This is useful for materials with smooth semi-transparent alpha such as results of a keyer. Note that transparent materials cannot intersect with each other, they only intersect with non transparent materials. You can however properly control their Z order by ordering the centroid of the bounding box of the object along the Z axis.
Alpha masked	Blending is disabled. This blending mode enables alpha masking. The alpha channel of the material's output defines whether a fragment is discarded or not using the Mask Threshold parameter. This is useful to properly intersect materials with completly opaque or completly transparent areas. Semi-transparent areas will be clipped according to Mask Threshold and may appear jaggy, use the Transparent blending mode instead in this case.
Multiply	Blending is enabled. The material's output is multiplied with the content of the render target, darkening the content.
Screen	Blending is enabled. Effectively the opposite of the multiply, the content of the render target is brightened.
Fade	Acts as Transparent but transparency is also applied to specular lighting. In Transparent mode, the material's alpha values only applies to diffuse lighting. This blending mode is useful to fade lit objects in and out.

Warning

The blending mode is ignored when using the Storm render delegate.

Blending mode and Depth AOV

When requesting the Depth AOV under Composition > 3D Settings, what is written in the depth buffer depends on the blending mode of the material:

Opaque: the alpha channel is ignored when writing the depth.
All other modes are equivalent to selecting Alpha Masking: the depth target is written only for pixels with an alpha value greater than the Mask Threshold specified on the material.