# SCNTube A tube or pipe geometry—a right circular cylinder with a circular hole along its central axis. ``` class SCNTube ``` ## Overview  The outer surface of a tube is a cylinder. Define the size of the cylinder’s cross section in the x- and z-axis dimensions of its local coordinate space with the [`outerRadius`](/documentation/SceneKit/SCNTube/outerRadius) property, and its extent in the y-axis dimension with the [`height`](/documentation/SceneKit/SCNTube/height) property. A cylinder becomes a tube through the subtraction of a cylindrical volume along its central axis. Define the size of this circular hole using the tube’s [`innerRadius`](/documentation/SceneKit/SCNTube/innerRadius) property. To position and orient a tube in a scene, attach it to the [`geometry`](/documentation/SceneKit/SCNNode/geometry) property of an [`SCNNode`](/documentation/SceneKit/SCNNode) object. Control the level of detail with the [`radialSegmentCount`](/documentation/SceneKit/SCNTube/radialSegmentCount) and [`heightSegmentCount`](/documentation/SceneKit/SCNTube/heightSegmentCount) properties. A higher radial segment count creates a smoother curve for the tube’s circular inner and outer surfaces. A higher segment count in either direction produces more vertices, which can improve rendering quality for certain lighting models or custom shader effects, but at a cost to rendering performance. A tube contains four [`SCNGeometryElement`](/documentation/SceneKit/SCNGeometryElement) objects: one each for its base and top, one that wraps around its outer surface, and one that wraps around its inner surface. SceneKit can render each element using a different material. For details, see the [`materials`](/documentation/SceneKit/SCNGeometry/materials) property in [`SCNGeometry`](/documentation/SceneKit/SCNGeometry). ## Topics ### Creating a Tube [`init(innerRadius:outerRadius:height:)`](/documentation/SceneKit/SCNTube/init(innerRadius:outerRadius:height:)) Creates a tube geometry with the specified inner radius, outer radius, and height. ### Adjusting a Tube’s Dimensions [`outerRadius`](/documentation/SceneKit/SCNTube/outerRadius) The radius of the tube’s outer circular cross section. Animatable. [`innerRadius`](/documentation/SceneKit/SCNTube/innerRadius) The radius of the circular hole through the tube. Animatable. [`height`](/documentation/SceneKit/SCNTube/height) The extent of the tube along its y-axis. Animatable. ### Adjusting Geometric Detail [`radialSegmentCount`](/documentation/SceneKit/SCNTube/radialSegmentCount) The number of subdivisions around the circumference of the tube. Animatable. [`heightSegmentCount`](/documentation/SceneKit/SCNTube/heightSegmentCount) The number of subdivisions in the inner and outer surfaces of the tube along its y-axis. Animatable. --- 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)