# portalSize The size of the portal window for immersive video playback, in meters. ``` var portalSize: SIMD2 { get set } ``` ## Discussion Use this property to control the dimensions of the portal window when [`desiredImmersiveViewingMode`](/documentation/RealityKit/VideoPlayerComponent/desiredImmersiveViewingMode) is [`VideoPlayerComponent.ImmersiveViewingMode.portal`](/documentation/RealityKit/VideoPlayerComponent/ImmersiveViewingMode-swift.enum/portal). The first component specifies the width and the second component specifies the height, both in meters. The default value is `[1.0, 0.5625]`, which produces a 16:9 aspect ratio. You can assign a new value before immersive playback transitions to portal mode, or while playback is already in portal mode to resize the portal in place. Both components must be greater than zero; if you assign a non-positive width or height, the property keeps its previous value. ```swift var component = VideoPlayerComponent(avPlayer: player) // Use a 4:3 immersive portal that's one meter wide. component.portalSize = [1.0, 0.75] // Render the immersive video into a portal window. component.desiredImmersiveViewingMode = .portal ``` This property doesn’t apply to spatial videos. --- 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)