Program Adaptation Requirements

LarkVR 3.2+ supports applications developed with Unity3D, Unreal, and Unigine (SteamVR-based), as well as applications based on OpenXR.

The management backend provides four VR application types:

- **VR (SteamVR shared):** The standard mode for shared VR applications built on SteamVR. No Steam account login is required.

- **VR (SteamVR exclusive):** Used for SteamVR applications that require a Steam account login. Only one application can run per machine, and users must log in to Steam before launching. **Note: As of V3.3.3.0, this type is disabled by default. To enable it, add the following property to `larkxr-center/application.properties`:**
    ```
    pxy.dispatch-policy.enable-exclude-mode=true
    ```

- **VR (OpenXR):** For applications built on the OpenXR standard.

## General Requirements

### 1. Supported Engines

Unreal Engine, Unity3D, DirectX 9/10/11/12, OpenGL.

### 2. Display Mode

Applications must launch in **windowed maximized mode**. Fullscreen exclusive mode is not supported for the following reasons:

- Fullscreen exclusive mode restricts the server to running only one application at a time.
- If the application resolution differs from the server resolution, the server display resolution will be forcibly changed.

> **Unity-specific:** Do **not** select the fullscreen option highlighted in the image below.

![https://showdoc.pingxingyun.com/Public/Uploads/2022-07-11/62cbd2fd723cb.png](https://showdoc.pingxingyun.com/Public/Uploads/2022-07-11/62cbd2fd723cb.png)

### 3. Application Architecture

Applications must be **purely 3D and single-process**. The following constraints apply:

- Only single-window process applications are supported (e.g., Unreal, Unity3D).
- Native Windows pop-ups are not supported; all UI must use graphics rendering.
- For applications developed with Qt and OpenGL: replace Qt controls with OpenGL/Widget so they are rendered within the scene. Qt controls will not be captured otherwise.
- Applications must not open external documents (Word, PDF, Excel, etc.) via system APIs.

## Requirements for VR (SteamVR Shared) and VR (NVIDIA VR Solution)

### Unreal Engine Applications

- **SteamVR must be installed** on the development machine. Without it, controller button inputs may not function correctly.

![/media/202605/d9bbdefadce342609bb8eacabbb6675a8574_20260529172504595913.png](/media/202605/d9bbdefadce342609bb8eacabbb6675a8574_20260529172504595913.png)

- **Enable "Start in VR"** in the project settings. The application will not launch in VR mode without this option.

![/media/202605/261718b1270a4ff09ee5678fd35174a97471_20260529172559152892.png](/media/202605/261718b1270a4ff09ee5678fd35174a97471_20260529172559152892.png)

## Requirements for VR (OpenXR)

- The **OpenXR plugin must be selected** within the application settings, as shown below:

![/media/202605/654b8f7584594525a55b4b7c391362332083_20260529172640477830.png](/media/202605/654b8f7584594525a55b4b7c391362332083_20260529172640477830.png)

## Packaging an Unreal Engine Project for Windows (VR)

Follow the steps below to package your Unreal Engine project for deployment as a VR application on Windows.

### Step 1 — Open the Plugins Menu

In your Unreal Engine project, navigate to **Edit** > **Plugins**.

![/media/202605/1_20260529173415180579.png](/media/202605/1_20260529173415180579.png)

### Step 2 — Enable the OpenXR Plugin

Search for **"OpenXR"** and enable the OpenXR plugin by checking the checkbox.

![/media/202605/2_20260529173440249529.png](/media/202605/2_20260529173440249529.png)

### Step 3 — Enable Start in VR

Ensure that **Start in VR** is enabled in the project settings.

![/media/202605/3_20260529173450042275.png](/media/202605/3_20260529173450042275.png)

### Step 4 — Package the Project

Go to **Platforms** > **Windows**, select **Shipping**, then click **Package Project**.

![/media/202605/4_20260529173512529115.png](/media/202605/4_20260529173512529115.png)

### Step 5 — Compress the Output

Once packaging is complete, compress the output folder into a ZIP archive for distribution.