XumLobby Build Guide
XRBuildKit + XumLobby — Quick‑Start Guide
This guide walks you through installing samples, configuring build settings, and building networked XR projects using XRBuildKit and XumLobby. Follow the steps in order for a smooth client‑and‑server build workflow.
1 Install the XRBuildKit Samples

Open Unity Package Manager → Window ▸ Package Manager.
Select XRBuildKit in the list.
In the Samples section, click Import to copy the demo DevicePresets and XumLobby sample scenes into your project.
Verify: Imported files appear under
Assets/Samples/XRBuildKit/
.
2 Set Up Scripting Defines

MST‑specific build features are enabled by the compile symbol USE_XUM_LOBBY
.
Edit ▸ Project Settings ▸ Player.
In Other Settings ▸ Scripting Define Symbols, add
USE_XUM_LOBBY
(semicolon‑separate if other defines exist).
Repeat for every platform you will build (e.g. Windows Server, Linux Server, Android Client).
Tip1 Let Unity finish recompiling after changing defines before attempting a build.
Tip2 If you just import the Device Preset Samples from 'Menu-XRBuildKit-Settings-XR Device Presets' and load 'StandaloneWindows64 / Win-Demo', the 'USE_XUM_LOBBY' define symbol will be set automatically.
3 Build & Run the XumLobby Sample
3.1 Open the Builder Window

XRBuildKit ▸ Build ▸ XR Builder – XumLobby.
3.2 Build the Server


Select the Server tab.
Choose the target OS (Windows or Linux).
Enter the Master / Room IP & Port (defaults OK for localhost tests).
Select the room scenes to include.
Tick options such as Headless Mode or Clean Build.
Click Master & Spawner (builds the main server binary).
Click Room (builds the room‑server binary).
3.3 Build the Client

Switch to the Client tab.
Enter the Master Server IP & Port (must match the server).
Pick a device preset (e.g. Quest3, PC).
Select scenes and build options.
Press Configure & Build. The entered IP/Port are written to the
ClientToMasterConnector
component in the scene.
3.4 Deploy & Run
For Linux server builds, use the integrated Deploy / Upload button on the Server tab, or copy the binary manually.
Start the server executable first, then launch the XR client. The client connects using the IP/Port configured above.
4 Troubleshooting Sample Builds
4.1 Missing XumLobby UI or Build Options
Ensure
USE_XUM_LOBBY
is present in Scripting Define Symbols for all relevant platforms.
4.2 Errors After Importing Samples
Re‑import the Samples via UPM.
Confirm that sample scenes and
DevicePresets
exist underAssets/Samples/XRBuildKit/
.
4.3 Build Fails (Plugin Conflicts / Duplicate Files)
Choose Clean Build.
Verify the selected Device Preset matches the current platform.
4.4 Connection Problems — Client Fails to Connect to Master Server
Confirm the server executable is running and listening on the specified IP/Port.
Verify that the Client build uses the same IP/Port (see Client tab ▸ Configure & Build).
Check firewall / network rules if server and client run on different machines.
Make sure the room server was built and is reachable by the master.
If issues persist, revisit the checklist above (defines, presets, clean build).
4.5 General Tips
Close the Project Settings window before saving/loading presets (avoids duplicate assets).
Delete
/Library/
and/Build/
caches if unexplained errors persist.After major configuration changes, always perform a Clean Build.
5 Remove or Reset the Samples (Optional)
Delete the imported folders under Assets/Samples/XRBuildKit/
, then re‑import via Package Manager at any time.
You are now ready to build and test networked XR apps with XRBuildKit and XumLobby!
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