# init(cubeFromEquirectangular:named:quality:faceSize:options:) Asynchronously creates a cube texture resource from an equirectangular image. ``` @MainActor @preconcurrency convenience init(cubeFromEquirectangular cgImage: CGImage, named resourceName: String? = nil, quality: TextureResource.SamplingQuality = .fast, faceSize: Int? = nil, options: TextureResource.CreateOptions) async throws ``` ## Parameters `cgImage` The source image. `resourceName` A unique name for syncing the texture resource across the network. The name is empty if you don’t include one. `quality` The sampling quality the initializer applies as it generates the cube texture. `faceSize` The dimension of a cube face. When `faceSize` is `nil`, RealityKit computes the size based on the equirectangular image’s dimensions. RealityKit clamps the value to the source image’s height. For best results, pass values that are one-third of the cubeʻs width or less. `options` A configuration for generating the texture. ## Discussion RealityKit samples the source equirectangular image at the specified quality level to generate the cube texture. The equirectangular image, also known as a *latitude-longitude image*, contains a flattened map of the surroundings where: - The width is a `360°` clockwise scan along the horizon, starting from behind (+z-axis) - The height is a -90° (bottom) to +90° (top) vertical scan To preserve all details equirectangular images require a `2:1` aspect ratio.  Use the resulting texture to create an [`EnvironmentResource`](/documentation/RealityKit/EnvironmentResource), or assign it to a material in Reality Composer Pro that requires a cube texture type. ```swift if let source = CGImageSourceCreateWithURL(url as CFURL, nil), let image = CGImageSourceCreateImageAtIndex(source, 0, nil) { // Create a cube texture from the image. let cube = try await TextureResource( cubeFromEquirectangular: image, quality: .normal, options: TextureResource.CreateOptions(semantic: .hdrColor)) // Create an environment resource from the cube texture. let environment = try await EnvironmentResource( cube: cube, options: EnvironmentResource.CreateOptions()) await MainActor.run { // Assign the environment to an image-based light component. let lightEntity = Entity() lightEntity.components.set( ImageBasedLightComponent(source: .single(environment))) ... } } ``` > Note: ``doc://com.apple.RealityKit/documentation/RealityKit/EnvironmentResource/CreateOptions/SamplingQuality-swift.enum/high`` and > ``doc://com.apple.RealityKit/documentation/RealityKit/EnvironmentResource/CreateOptions/SamplingQuality-swift.enum/veryHigh``, along with > ``doc://com.apple.RealityKit/documentation/RealityKit/TextureResource/Compression/astc(blockSize:quality:)`` compression options, are only available in macOS. > Use these options to write optimized scenes for all target platforms when exporting from macOS with ``doc://com.apple.RealityKit/documentation/RealityKit/Entity/write(to:)``. > Compression options also significantly reduce a cube’s memory and disk usage. --- 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)