How to create custom wings (Custom Wings) on your MU Online server
Add exclusive wings to your MU Online server: choosing the item slot, importing the 3D model (BMD) and textures into the client, registering the item in the server's ItemList, options, levels and crafting at the Chaos Machine — with full in-game testing.
Exclusive wings are one of the biggest draws of a MU Online server: they give visual identity, become an object of desire and feed the shop and events. But "custom wings" is a two-sided project — client (the 3D model and textures the player sees) and server (the item registration, options and crafti
Exclusive wings are one of the biggest draws of a MU Online server: they give visual identity, become an object of desire and feed the shop and events. But "custom wings" is a two-sided project — client (the 3D model and textures the player sees) and server (the item registration, options and crafting). Skipping either side results in invisible wings, a client crash or an item nobody can create. This tutorial walks through both sides from start to finish.
What custom wings are
In MU, wings are an item like any other, with a type (category) and an index. What makes them "wings" is: (1) being in the wings item type, (2) having a 3D model (a BMD file) and textures (OZJ/OZT) on the client, and (3) having options and levels registered on the server. Custom wings are simply wings at a free index, with their own model and textures.
Prerequisites
- A running MU server and a matching client already working.
- An update launcher to distribute the new files to players.
- A tool to pack/unpack
Item.bmd(a community BMD editor). - A wing BMD model (your own or from a pack) and its textures.
- A backup of the client and the server.
Files involved
| Side | File | Function |
|---|---|---|
| Client | Data/Item/WingXX.bmd | The wings' 3D model |
| Client | Data/Item/WingXX.OZJ/OZT | The wings' textures |
| Client | Data/Local/Item.bmd (or Text) | Name/description on the client |
| Server | ItemList.xml / Item.txt | Item registration (type 12) |
| Server | Chaos Machine config | Crafting recipe |
Step 1 — Choose the slot (type 12 + a free index)
Open the item list for type 12 (wings) and pick an unused index. Write down the type:index pair (e.g. 12:130) — it will be your wings' identity across every file. Never reuse the index of official wings: players who already have those wings would find the item swapped or corrupted.
Step 2 — Import the 3D model (BMD) and textures into the client
- Place
WingXX.bmdand the texture files (.OZJ/.OZT) in the client'sData/Item/folder. - If the model came "raw" (not encrypted), encrypt it to your client's format with the BMD editor.
- Make sure the file name matches the index the client expects for that item (the convention varies by season; follow the pattern of the wings already in the folder).
Step 3 — Register the wings on the server (ItemList)
In ItemList.xml/Item.txt, add the item line under type 12, the chosen index, defining: name, item level, slots, whether it accepts excellent/ancient, durability and allowed class. An incomplete registration makes the item exist but not equip — check each column against a working official pair of wings as a reference.
Step 4 — Configure the wings' options and levels
This is where the wings gain power. Define:
| Option | Suggested range |
|---|---|
| Damage absorption | 5% to 45% (per +level) |
| Damage increase | 5% to 39% |
| Additional option bonus | +attack/+defense/+HP |
| Maximum level | +0 to +15 |
Compare with the official wings of your season so you don't create a disproportionate item. Custom wings should be desirable, not broken.
Step 5 — Configure crafting (Chaos Machine)
For the player to obtain the wings, set the recipe at the Chaos Machine: input items (previous-tier wings, jewels, event items), success rate and the output item (your custom wings). Start with a moderate rate (50–70%) and adjust to the market. Alternatively, distribute them via boss drop or the VIP shop.
Step 6 — Distribute to the client and test
- Pack the new files and publish the update through the launcher.
- Update the anti-cheat/launcher verification list to include the new BMD/textures.
- Log in with the GM, generate the wings and equip them — confirm the model appears correctly.
- Test on another class and at another resolution, to make sure there is no crash.
- Test the crafting at the Chaos Machine with a regular account.
Common errors and fixes
| Symptom | Likely cause | Fix |
|---|---|---|
| Wings invisible when equipped | BMD/texture missing on the client | Confirm the files in the Item folder and the distribution |
| Crash when equipping | Corrupted BMD or wrong encryption | Re-export/re-encrypt the model |
| Item won't equip | Incomplete registration in the ItemList | Compare columns with an official pair of wings |
| Anti-cheat false positive | Hash not updated | Update the launcher's verification list |
| Nobody can craft it | Wrong Chaos Machine recipe | Review the input items and rate |
Launch checklist
- Free item index chosen (type 12) and recorded.
- BMD + textures on the client, correctly encrypted.
- Item registered in the ItemList and equipping in-game.
- Options and levels balanced vs. official wings.
- Crafting recipe (Chaos Machine/drop/shop) defined.
- Update distributed through the launcher and anti-cheat adjusted.
- Full test (equip, craft, switch class/resolution).
With your first custom wings live and tested, you have a reusable pipeline: for the next pair, just repeat the steps with a new index and model. Document the type:index of each custom wing in a spreadsheet — this avoids collisions when your catalog grows.
Frequently asked questions
Do I need to know 3D modeling to have custom wings?
Not necessarily. You can use ready-made models (BMD) shared by the community and just import them. Modeling from scratch requires specific BMD tools; most servers start with ready-made packs and only swap textures.
Do custom wings need to be installed on every player's client?
Yes. The model (BMD) and the textures live on the client. So when you launch new wings, you need to distribute the update through the launcher — otherwise the player sees the wings as an invisible or broken item.
Do Custom Wings break the anti-cheat / file verification?
They can, if your system validates the hash of the client files. When you add new files, update the launcher/anti-cheat verification list to include the new BMD and textures, avoiding a false positive.
Which item slot should I use for the new wings?
Wings live in item type 12 (the wings category) in almost every emulator. Use a free index within that type — avoid overwriting existing official wings, or you break items players already own.
Can I put exclusive options on custom wings?
Yes. In the item registration you define the options (damage, defense, absorption, elemental bonus) and the levels (+0 to +15). That is where you set the custom wings apart from the official ones — but be careful with balance so you don't create a disproportionate 'pay-to-win' item.