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# base

Another material object from which this material’s properties are derived.

```
var base: MDLMaterial? { get set }
```

## Discussion

When you use the [`property(with:)`](/documentation/ModelIO/MDLMaterial/property(with:)), [`propertyNamed(_:)`](/documentation/ModelIO/MDLMaterial/propertyNamed(_:)), or [`subscript(_:)`](/documentation/ModelIO/MDLMaterial/subscript(_:)-323j3) method to access material properties, the [`MDLMaterial`](/documentation/ModelIO/MDLMaterial) class first checks whether the material itself has a material property with the specified name or semantic. If not, those methods forward to the corresponding method of the other [`MDLMaterial`](/documentation/ModelIO/MDLMaterial) object specified by this property.

Use this method to create sets of materials that share most of their material properties but differ in others. For example, you can have a set of objects in the same scene with the same general style of surface appearance (determined by the [`scatteringFunction`](/documentation/ModelIO/MDLMaterial/scatteringFunction) property) but with different values for the [`baseColor`](/documentation/ModelIO/MDLScatteringFunction/baseColor) material property.

---

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