Spatial Swiftui Developer

Spatial SwiftUI Developer

Description and Goals

This skill provides guidance for designing and implementing visionOS SwiftUI scenes that integrate RealityKit content. It helps you choose between SwiftUI and RealityKit APIs for 3D presentation and shows how to bridge between the two frameworks effectively.

Goals

• Enable developers to build spatial UI experiences on visionOS
• Guide selection between SwiftUI and RealityKit APIs for 3D content
• Show how to integrate RealityKit content into SwiftUI scenes
• Demonstrate spatial interaction patterns with gestures
• Support proper windowing and immersion patterns

What This Skill Should Do

When building spatial UI with SwiftUI on visionOS, this skill should:

1. Guide presentation surface selection - Help you choose between WindowGroup, volumetric windows, and ImmersiveSpace
2. Select 3D APIs - Show when to use Model3D vs RealityView for different use cases
3. Integrate RealityKit - Demonstrate how to load and embed RealityKit content in SwiftUI
4. Handle spatial interaction - Provide patterns for spatial gestures and entity-targeted interactions
5. Manage lifecycle - Ensure proper async loading and state management

Load the appropriate reference file from the tables below for detailed usage, code examples, and best practices.

Quick Start Workflow

1. Identify the presentation surface: WindowGroup, volumetric window, or ImmersiveSpace.
2. Choose a 3D API: Model3D for simple models, RealityView for full RealityKit scenes.
3. Load RealityKit content asynchronously and add entities in the RealityView make closure.
4. Use either Attachment plus RealityViewAttachments.entity(for:) or ViewAttachmentComponent to place SwiftUI UI in 3D space when needed.
5. Add spatial interaction with SpatialTapGesture or entity-targeted gestures.
6. Update RealityKit content in the RealityView update closure, not in SwiftUI body.
7. Use defaultSize when you want a predictable initial volumetric size, and use immersionStyle to configure immersive spaces.

Information About the Skill

Core Concepts

Scene and Spatial Presentation

• Use WindowGroup with windowStyle(.volumetric) for volumes. Add defaultSize when you want a predictable initial size, but treat it as a hint rather than a hard guarantee.
• Use ImmersiveSpace for unbounded spatial scenes and immersionStyle selection.
• Use openImmersiveSpace and dismissImmersiveSpace for transitions.

RealityKit Embedding in SwiftUI

• Use RealityView for full RealityKit scenes and per-frame updates.
• Use Attachment and RealityView attachments to embed SwiftUI views in 3D.
• Use ViewAttachmentEntity and ViewAttachmentComponent for attachment entities.

3D Model Presentation

• Use Model3D for async model loading with SwiftUI layout.
• Use Model3DPhase and Model3DAsset for loading phases and animation choices.

Spatial Input

• Use SpatialTapGesture for spatial tap locations in 2D/3D coordinate spaces.

Reference Files

Implementation Patterns

• Use Model3D when you only need display and layout; use RealityView for custom entity graphs and systems.
• Keep RealityKit mutations inside RealityView make/update closures.
• Prefer attachments for UI that should remain SwiftUI-driven but positioned in 3D.
• Treat ImmersiveSpace as a separate scene with its own lifecycle and environment actions.

Pitfalls and Checks

• Do not block the main actor with synchronous model or entity loading.
• Do not update RealityKit entities inside SwiftUI body computation.
• Do not use volumetric window style with Window instead of WindowGroup.
• Do not treat defaultSize as a hard requirement or guaranteed final size; the system can clamp or restore window geometry.
• Use .glassBackgroundEffect() when you want the system glass treatment on visionOS, and use custom backgrounds deliberately when the design needs a different visual language.