As described in the Datasmith Overview, the Datasmith import process creates a new Material Asset in the Unreal Engine Project to represent each different set of geometry surface properties it recognizes in the scene it imports. Although the goal of the scene transformation is to carry over surface properties with the best possible fidelity, you'll likely need to tweak these Materials after import. You can double-click any Material Asset to edit it.
Most of the Material Assets that you'll find in the Materials folder are Material Instances. That means that when you edit the Material Instance, you'll see a pre-set list of settings that are determined by its parent or master Material. For example, the following image shows a Material Instance created for a model imported from SketchUp:
For more information about what Material Instances are and how to work with them, see Instanced Materials and the Material Instance Editor User Guide.
Each Material Instance also has a Parent Material: a different kind of Material Asset that contains a node graph similar to a Blueprint. This graph determines the actual operations that are carried out on the GPU when the Unreal Engine needs to render a surface that has the Parent Material or any of its Material Instances applied. The way the Parent Material's graph is constructed also controls the settings that are exposed in its Material Instances, and how those settings are used.
Datasmith assigns your Material Instances different Parent Materials depending on your source application, according to the following principles:
- In most cases, Datasmith assigns each Material Instance a pre-existing Parent Material that is included as part of the Datasmith plugin. Typically, the pre-defined settings exposed by these Parent Materials are very similar to the material authoring settings that are available in your source application.
You can freely edit these exposed settings in each Material Instance that Datasmith creates in your Project. Each different Parent Material offered by Datasmith offers a different set of properties:
- Datasmith_Color - This Parent Material is used for solid colors and textured surfaces, mostly when importing CAD models. See The Datasmith Color Material below.
- SketchUpMaster - This Parent Material is used for all surfaces imported from SketchUp. See Using Datasmith with SketchUp Pro.
- RevitMaster - This Parent Material is used for all surfaces imported from Revit. See Using Datasmith with Revit.
- Datasmith_Material - This Parent Material is used for textured surfaces imported from Rhino. See Using Datasmith with Rhino.
- If you're importing content from 3ds Max, you may find that Datasmith also creates new Parent Materials in your Project, inside the Materials/Master folder. 3ds Max offers a much richer Material authoring workflow than most other source applications, and one that is conceptually similar to Unreal Engine Material graphs. Therefore, Datasmith is typically able to create new Master Materials that are very close to the custom Materials you have in 3ds Max, rather than having to reuse pre-set Parent Materials that have a pre-set graph and a pre-set list of exposed settings.
In this case, Datasmith still creates Material Instances for those custom Parent Materials and applies those Material Instances to your Static Mesh Assets and Actors. In most cases, modifying the properties of the Material Instances should be enough to give you a good level of control over the rendered results.
If you want to alter the actual Material graph that a Material Instance uses to determine how to shade the surface based on those properties, you need to duplicate the Parent Material and modify the properties in your duplicate. For details on this process, see Modifying a Datasmith Master Material.
Another option, instead of working with the Materials created by Datasmith, is always to completely replace the Material created by Datasmith with another physically based Material. This could be a Material that you create yourself in the Unreal Editor, or from a third-party.
With your Unreal Studio subscription, you have access to a library of 100 physically based Substance Materials from Allegorithmic. To get started, see here