This pages describes the synergies between Substance graphs and MDL graphs, and how to connect textures from Substance graph outputs to MDL graph inputs.

Overview

The outputs of Substance graphs can be passed to exposed parameters of MDL materials in two ways, which are described in this page.

If the MDL material currently applied in the 3D view has exposed parameters which type is varying – this type may be set using the Type modifier option in the exposed parameter's properties, these can be connected to textures:

• a Color parameter can be connected to RGBA textures
• a Float parameter for Grayscale textures

In these cases, the raw uniform value is replaced by a texture sampler supplying a varying value. These samplers have a usage attribute defined in the exposed parameter, and this usage lets Designer connect textures output by Substance graphs to the appropriate parameter in the MDL material, by matching usages.

Substance graphs in the 3D View

When using the View outputs in 3D View option for a Substance graph or dragging a Substance graph from the Explorer panel to the 3D view, the outputs are connected to the exposed parameters of matching usages in the MDL material currently displayed in the 3D view.

Individual textures from a Substance graph may be connected to any of the MDL material parameters which support texture sampling, regardless of the identifier, by pressing RMB on the Substance graph node and dragging into the 3D view. A list of available sampler usages is displayed, and you may select the target usage for the selected texture.

Textures output by a Substance graph are connected to an MDL graph's exposed parameters in the 3D View

Substance graphs in MDL graphs

Substance graph instances can be placed directly into MDL graphs by dragging them from the Explorer panel into the MDL graph. Substance graphs from both Substance 3D files (SBS) and Substance 3D asset files (SBSAR) may be used in MDL graphs.

When a Substance graph instance is created, it appears as a node with the following features:

• A typed output connector for each of the graph’s outputs. The output data is typed as follows:
  • RGBA bitmaps: Color (varying)
  • Grayscale bitmaps: Float (varying)
  • Values: Match the value type (varying)
• An input of type UV coordinates to specify the UV coordinates which should be used to map the textures output by the Substance graph. If left unconnected, the default value is a classic 0-1 linear gradient in X and Y in UV space
• The node is labelled after the Substance graph label – or identifier if no label is defined – and its first bitmap output as a thumbnail

The node properties let you modify all dynamic properties of the Substance graph:

• Output size
• Random seed
• Input parameters
• …

The node properties also let you set parameters specific to how textures are mapped in the MDL material:

• Tiling
• Use Physical size
• Normal format
• Tangent space

The Substance graph instance node’s output may be connected to any node input of matching type in the MDL graph.

Please note changing any parameter in the SBS Base parameters section involves recomputing one or more of the Substance graph outputs, which uses the Substance engine and involves a performance overhead on top of the MDL graph computations. Expect a performance impact when modifying a Substance graph which is instanced in an MDL graph applied in the 3D view.