Multi-Instance Isolation

Quest 3D WebView is built from the ground up to support multiple concurrent web screens running simultaneously in the same 3D VR environment.

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How Multi-Instance Isolation Works

When multiple BP_WebScreen actors are placed in a level or spawned dynamically at runtime:

1. On BeginPlay, each component receives an unconditionally incremented, unique runtime InstanceId (NextInstanceId++).
2. In the Android layer, each InstanceId creates its own dedicated:
   • Android VirtualDisplay instance
   • ImageReader swapchain
   • Chromium WebView container
   • Dedicated render update handler thread

                     Unreal Engine 5 VR Level
  ┌───────────────────────┬───────────────────────┬───────────────────────┐
  │  Screen 1: ChatGPT    │  Screen 2: YouTube    │  Screen 3: Trello     │
  │  Instance ID = 1      │  Instance ID = 2      │  Instance ID = 3      │
  └───────────┬───────────┴───────────┬───────────┴───────────┬───────────┘
              │                       │                       │
              ▼                       ▼                       ▼
      VirtualDisplay #1       VirtualDisplay #2       VirtualDisplay #3
      (TargetFPS = 30)        (TargetFPS = 60)        (TargetFPS = 30)

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Naming & Identifying Instances

To make it easy to build UI docks, switchers, and dropdowns:

• InstanceName (Property): Set a descriptive label in the Details Panel (e.g. "Primary YouTube", "ChatGPT Workspace").
• SetInstanceName(InName) / GetInstanceName() (Nodes): Dynamically read or update labels from Blueprint.
• GetInstanceId() (Node): Returns the numeric internal instance identifier.

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Recommended Multi-Instance Best Practices

To maintain a rock-solid 72+ FPS on Meta Quest when running 3 to 6 active screens:

1. Stagger Video Framerates:
   • Keep your primary video screen at TargetFPS = 60.0.
   • Set secondary static screens (ChatGPT, Trello, Discord) to TargetFPS = 30.0.
2. Use 720p on Secondary Panels:
   • Set secondary panels to Width = 1280, Height = 720 to reduce GPU texture memory overhead by 55%.
3. Pause Out-of-Sight Panels:
   • Call PauseRendering() on screens that are positioned behind the player's field of view.