# materials An array of [`SCNMaterial`](/documentation/SceneKit/SCNMaterial) objects that determine the geometry’s appearance when rendered. ``` var materials: [SCNMaterial] { get set } ``` ## Discussion Materials provide the information SceneKit uses to add color, lighting, texture, and special effects when rendering a geometry. Each [`SCNMaterial`](/documentation/SceneKit/SCNMaterial) object can be shared between several geometries. If a geometry contains multiple elements (see [`elementCount`](/documentation/SceneKit/SCNGeometry/elementCount)), you can associate a separate material with each geometry element. For example, the teapot in [Figure 1](/documentation/scenekit/scngeometry/1523472-materials#1965912) has four elements, each with a different material.  If a geometry has the same number of materials as it has geometry elements, the material index corresponds to the element index. For geometries with fewer materials than elements, SceneKit determines the material index for each element by calculating the index of that element modulo the number of materials. For example, in a geometry with six elements and three materials, SceneKit renders the element at index `5` using the material at index `5 % 3 = 2`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)