# SCNGeometryElement A container for index data describing how vertices connect to define a three-dimensional object, or geometry. ``` class SCNGeometryElement ``` ## Overview You use geometry elements together with [`SCNGeometrySource`](/documentation/SceneKit/SCNGeometrySource) objects to define custom [`SCNGeometry`](/documentation/SceneKit/SCNGeometry) objects or to inspect the data that composes an existing geometry. You create a custom geometry using a three-step process: 1. Create one or more [`SCNGeometrySource`](/documentation/SceneKit/SCNGeometrySource) objects, each of which defines per-vertex information such as position, surface normal, or texture coordinates for all vertices in the geometry. 2. Create at least one [`SCNGeometryElement`](/documentation/SceneKit/SCNGeometryElement) object, containing an array of indices identifying vertices in the geometry sources and describing the drawing primitive that SceneKit uses to connect the vertices when rendering the geometry. 3. Create an [`SCNGeometry`](/documentation/SceneKit/SCNGeometry) instance from the geometry sources and geometry elements. When SceneKit renders a geometry, each geometry element corresponds to a drawing command sent to the GPU. Because different rendering states require separate drawing commands, you can define a geometry using multiple geometry elements. For example, the teapot geometry shown below has four geometry elements, so you can assign up to four [`SCNMaterial`](/documentation/SceneKit/SCNMaterial) objects in order to render each element with a different appearance. But because each drawing command incurs a CPU time overhead when rendering, minimizing the number of elements in a custom geometry can improve rendering performance.  ## Topics ### Creating a Geometry Element [`init(indices:primitiveType:)`](/documentation/SceneKit/SCNGeometryElement/init(indices:primitiveType:)) Creates a geometry element from the specified array of index values. [`+ geometryElementWithData:primitiveType:primitiveCount:bytesPerIndex:`](/documentation/SceneKit/SCNGeometryElement/init(data:primitiveType:primitiveCount:bytesPerIndex:)) Creates a geometry element from the specified data and options. [`+ geometryElementWithMDLSubmesh:`](/documentation/SceneKit/SCNGeometryElement/geometryElementWithMDLSubmesh:) Creates a geometry element from the specified Model I/O submesh object. ### Working with Indexes [`data`](/documentation/SceneKit/SCNGeometryElement/data) The data describing the geometry element. [`bytesPerIndex`](/documentation/SceneKit/SCNGeometryElement/bytesPerIndex) The number of bytes that represent each index value in the element’s data. [`primitiveType`](/documentation/SceneKit/SCNGeometryElement/primitiveType) The drawing primitive that connects vertices when rendering the geometry element. [`SCNGeometryPrimitiveType`](/documentation/SceneKit/SCNGeometryPrimitiveType) The drawing primitive that connects vertices when rendering a geometry element, used by the [`primitiveType`](/documentation/SceneKit/SCNGeometryElement/primitiveType) property to specify how SceneKit interprets the geometry element’s data. [`primitiveCount`](/documentation/SceneKit/SCNGeometryElement/primitiveCount) The number of primitives in the element. [`primitiveRange`](/documentation/SceneKit/SCNGeometryElement/primitiveRange) The range of primitives from the geometry element to render. ### Rendering Point Clouds Use these properties to display a geometry as a collection of points, rather than as a solid surface or wireframe. [`pointSize`](/documentation/SceneKit/SCNGeometryElement/pointSize) The width of each point in the geometry element, as measured in the geometry’s local 3D coordinate space. [`minimumPointScreenSpaceRadius`](/documentation/SceneKit/SCNGeometryElement/minimumPointScreenSpaceRadius) The smallest radius, measured in screen points, at which to render any point in the geometry element. [`maximumPointScreenSpaceRadius`](/documentation/SceneKit/SCNGeometryElement/maximumPointScreenSpaceRadius) The largest radius, measured in screen points, at which to render any point in the geometry element. ## Relationships ### Conforms To [`Equatable`](/documentation/Swift/Equatable) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) [`CVarArg`](/documentation/Swift/CVarArg) [`NSSecureCoding`](/documentation/Foundation/NSSecureCoding) [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`NSCoding`](/documentation/Foundation/NSCoding) [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`Hashable`](/documentation/Swift/Hashable) ### Inherits From [`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class) --- 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)