# Mesh Optimizer

Imported clothing is often much heavier than it needs to be: duplicate vertices, broken geometry and no LODs. The **Mesh Optimizer** cleans a model up, can cut its triangle count, and can build the distance versions the game swaps to. Nothing is written until you press **Apply**, and the original can always be restored.

:::hint{type="info" title="Premium"}
The Mesh Optimizer is a **Premium** feature.
:::

## Opening it

- In the item panel, click the **Mesh** tool tile (*Polygons and LODs*).
- Right-click an item and choose **Optimize mesh…**.
- Select several items, right-click and choose **Optimize meshes in the selected items…**. The same settings apply to every item, and the button reads **Apply to *n* items**.

## Easy: pick a preset

| Preset | What it does |
| --- | --- |
| **Tidy up** | Removes broken and duplicate geometry only. Nothing about how the garment looks changes. |
| **Add distance versions** | Tidies up and adds the Med, Low and VeryLow levels the game uses when the ped is far away. The full-detail model is untouched, so the file gets bigger, not smaller. |
| **Lighter model** | Tidies up, adds the distance versions, and drops 30 % of the triangles. This is the only preset that changes the garment's shape, so compare the wireframes before applying and check it in the viewport afterwards. |

## Advanced: every setting

Switch to **Advanced** to set each step yourself. Each setting has a **?** beside it.

1. **Clean up**: removes degenerate triangles and vertices nothing uses. Always safe.
2. **Weld vertices**: merges vertices that sit on top of each other, within a **Distance**. Two vertices are only merged when their position, normal, UV and bone weights all agree, so hard edges, UV seams and skinning survive. **Keep edges sharper than** (25° by default) sets the angle that stays a hard edge.
3. **Decimate**: off by default. It collapses triangles while keeping the silhouette, down to the share you set under **Keep** (5–100 % of triangles, 50 % by default). This is the step that changes how the garment looks.
4. **Generate LODs**: builds the Med, Low and VeryLow levels from the result.

## Before and after

:::frame{caption="Before and after, side by side, with the triangle count."}
![The Optimize mesh window showing a vest before and after side by side, with the triangle count halved and the clean up, weld and decimate settings](https://pub-57d6558d0e204696b4cdeee5d172e561.r2.dev/cloth-tool/features/mesh-optimizer.710b59ffb8.webp)
:::

New in 2.0.8, the window shows a large before/after preview of the model:

- **Side by side** shows the model before and after, or pick **Before** or **After** on its own. Choose **Shaded**, **Shaded + wire** or **Wire only**, and turn on **Textures** to see the garment's texture.
- Drag to turn, right-drag or Shift-drag to move, and use the wheel to zoom. Both sides follow. Double-click or **Reset view** goes back to the front view.
- The counters show vertices and triangles before and after, and how many triangles are removed.

Change the settings until the trade-off looks right, then press **Apply**.

## Applying and restoring

- **Apply** rewrites the model in this project. The live preview and the next build use it straight away. The window then shows the size written on disk.
- Before the first apply, a copy of the original is kept beside the model as an `.optbak` file. **Restore original** puts it back at any time, even after closing the app.
- An optimise can also be undone with **Ctrl+Z**.

:::hint{type="success" title="Rule of thumb"}
Start with **Tidy up** on everything. Use **Lighter model** or decimation on your heaviest models, such as jackets and layered tops, and check them in the viewport. Add distance versions to garments that many players will wear on a busy server.
:::

## Related pages

- [Model Studio](/cloth-tool/about-the-tool/model-studio): edit the mesh by hand, including merge by distance on a selection.
- [Texture Optimization](/cloth-tool/about-the-tool/texture-optimization): shrink the textures as well.
- [Building](/cloth-tool/about-the-tool/building): what goes into the pack.
- [Limits](/cloth-tool/information-and-errors/limits): what the game tolerates.