FishNet Multiplayer Addon

Make FBSystem scenes and players multiplayer-ready with the optional FBSystemFishNet addon: client-authoritative movement, animator and item sync, networked world items, and a dedicated Setup Wizard.

On this page

1. What the addon does
2. Requirements
3. 1. Install FishNet and the addon
4. Video: FishNet quick setup
5. 2. FishNet Setup Wizard
6. Step 1: Scene Setup
7. Step 2: Select Player
8. Step 3: FishNet Components
9. Step 4: World Items
10. Step 5: Validation
11. 3. Networked world items
12. What gets synchronized
13. Not included by design
14. Testing host & remote client
15. Host test in the editor
16. Remote-client test
17. Troubleshooting

What the addon does#

An optional package that lives in Assets/FBSystemFishNet/. It turns any scene and any FBSystem player into a FishNet-multiplayer setup without touching the base package.

• A 5-step Setup Wizard wires the NetworkManager, the player bridge and world items. Every step is idempotent: existing objects are reused.
• FishNetPlayerBridge syncs movement, animator state, look pitch and item equipment, and auto-discovers owner-only components (ItemSwitcher, PlayerInteraction, PlayerDropSystem).
• FishNetFPCutterVisibility hides the head for the local player (no FP clipping) and shows the full body on every remote.
• A drag-and-drop world-item window creates _Net variants, registers them, and fills the bridge prefab list.
• A prepared demo scene is included.

Requirements#

1. Install FishNet and the addon#

1. Import FishNet (4.7.2) into your Unity project.
2. Import the optional FBSystemFishNet addon folder or package.
3. Open the scene you want to make multiplayer-ready.

Video: FishNet quick setup#

The five wizard steps from an empty scene to a host test.

Open on YouTube (opens in a new tab) if the embed is blocked. Video ID: BN9u25nHWHw

2. FishNet Setup Wizard#

Menu: Tools ▸ FBSystem ▸ FishNet ▸ Setup Wizard. The wizard has five steps with a progress bar, < Back and Next > buttons, and Finish Setup on the last step. It lives only in Assets/FBSystemFishNet and does not change core files under Assets/FBSystem. To export the addon as a .unitypackage, export only the FishNet folder.

Step 1: Scene Setup#

Prepares the open scene as a FishNet host:

• Creates or reuses a NetworkManager with Tugboat transport (default port 7770), ObserverManager, PlayerSpawner, spawnable-prefab wiring and an EventSystem.
• Instantiates FishNet's own NetworkHudCanvas prefab (Assets/FishNet/Demos/Prefabs/NetworkHudCanvas.prefab) for Start Server and Start Client. If the FishNet demos were removed, the wizard warns: restore the prefab.
• All status rows turn green: NetworkManager, TransportManager + Tugboat, PlayerSpawner, Connection HUD, EventSystem. The button ✨ Make Scene FishNet Ready runs this step.

Step 2: Select Player#

Select the FBSystem player GameObject from the Hierarchy. It must be a scene instance, not a plain prefab asset, and must carry PlayerController, Animator and the other components. The wizard adds NetworkObject and FishNetPlayerBridge, and reconfigures the bridge if it already exists.

• Field Player Root: None (Game Object). Drag the instance from the scene into it.
• Yellow hint: Drag your player from the Hierarchy (scene instance). Prefab assets must be in a scene.
• If you use FPCutter, FishNetFPCutterVisibility is wired automatically: the head is hidden locally and fully visible remotely.

Step 3: FishNet Components#

Adds and configures the network components without changing core FBSystem files:

• NetworkObject, NetworkTransform (CharacterController, ClientAuth), NetworkAnimator (ClientAuth, Animator ref), FishNetPlayerBridge and FishNetFPCutterVisibility (local = FirstPerson / remote = ThirdPerson), each with a green check.
• When an FPCutter mesh is detected, the info line reads: FPCutter mesh detected — FishNetFPCutterVisibility will hide Head for local player (no camera clipping) and show full body for remotes.
• Button ✨ Configure FishNet Components. The Recent Changes list then shows Configured NetworkObject / NetworkTransform / NetworkAnimator and FishNetFPCutterVisibility already present.

Step 4: World Items#

Converts WorldItem prefabs to networked variants: it adds NetworkObject and NetworkTransform, creates *_Net.prefab files under Assets/FBSystemFishNet/Testing/WorldItems/ and registers them as spawnable.

• Example from the screenshot: Found 2 item(s) in ItemContainer → [0] 1 -> Flashlightworlditem, [1] 2 -> Box_worlditem.
• Buttons ✨ Setup Networked World Items (from ItemContainer) and Open WorldItem Setup Window (Drag & Drop, Find All, Remove) for manual management.
• To add items freely by drag and drop, use Tools ▸ FBSystem ▸ FishNet ▸ Setup Networked World Items (separate window).

Step 5: Validation#

Final health check. Fix any remaining warnings. This step does not change core FBSystem files.

• On success: ✨ All checks passed — the scene and player are ready for FishNet. Press Play and use FishNet's HUD buttons (Start Server / Start Client).
• Button Select NetworkManager in Scene and the Export section: to ship the addon as a .unitypackage, select the Assets/FBSystemFishNet folder, right-click, and choose Export Package. The core Assets/FBSystem folder stays untouched and works without FishNet.
• Close the wizard with Finish Setup. If needed, the wizard generates a GeneratedPlayers/*_Network prefab asset, so PlayerSpawner never holds a scene instance. This fixes PrefabId 65535 and NullReference errors on spawn.

Owner-only behaviours (ItemSwitcher, PlayerInteraction, PlayerDropSystem) are detected automatically on the bridge.

3. Networked world items#

Menu: Tools ▸ FBSystem ▸ FishNet ▸ Setup Networked World Items opens a drag-and-drop window (NetworkWorldItemSetupWindow). Use Find All WorldItems and add or remove entries before applying. Auto-Find Bridge and ItemContainer integration are available. The window:

• Creates _Net WorldItem variants.
• Registers them with FishNet.
• Fills the bridge's prefab list on the player.

Pickup despawns the server object. A drop spawns a networked WorldItem that is visible to all clients (server authoritative).

What gets synchronized#

Not included by design#

Testing host & remote client#

The addon ships a prepared test setup. The scene is not in Build Settings, so add it before you build a remote client:

• Scene: Assets/FBSystemFishNet/Testing/Demo.unity
• Player: Assets/FBSystemFishNet/Testing/FBSystemNetworkPlayer.prefab
• Collection: Assets/FBSystemFishNet/Testing/FBSystemFishNetPrefabs.asset

Host test in the editor#

1. Open Demo.unity. It must contain the FishNet NetworkManager and its PlayerSpawner.
2. Press Play. The HUD shows Start Server and Start Client. Start both for a host test.
3. Verify movement, jump, sprint, crouch, root rotation, remote animator state and look pitch. The remote player must not process local input.
4. Switch items (number keys, Q, or scroll) and verify equip/unequip on the other instance. Item use stays local.
5. Stop the client first, then the server. Check the Console for bridge errors or movement-sanity warnings.

Remote-client test#

1. Add Demo.unity to Build Settings and build it for Windows.
2. Run the build as the client and the editor scene as the host.
3. Start the server in the editor and the client in the build with the HUD buttons.
4. Repeat the same verification as above across both instances.

Troubleshooting#