# Re-Tessellate

> How to re-tessellate parts in Asset Transformer Studio

Models that contain BRep surfaces (CAD models) can be re-tessellated directly in the scene without having to import the model all over again. Re-Tessellate allows you to fine-tune tessellation quality of entire models or individual [parts](../glossary#part) in the scene.

See [About Tessellation](./_index.md).

## Condition

Parts can be re-tessellated providing they were originally tessellated with Asset Transformer Studio, using the [Tessellate](/asset-transformer-studio/2026.5.0/api/python/algo_functions.md#tessellate) function, and with the parameter `Keep BRep Shape` enabled.

## Notes

Here are a few important notes when re-tessellating parts:

* Refining the tessellation parameters values will produce smoother surfaces on your model, but also increase [polycount](http://wiki.polycount.com/wiki/Polygon_Count) and the scene file size.
* When re-tessellating, meshes are entirely recreated, so actions like [mesh repair](../../user-interface/menu-bar/mesh-menu/repair-mesh), face orientation corrections and UVs generation need to be executed again on the newly created mesh. So, it is advised to fine-tune tessellation quality right after import and initial tessellation, prior to moving on to fixing and optimizing meshes.
* When clicking one of the `Re-Tessellate` actions, it's the `Tessellate` dialog box that is opened, and the parameter `Override Existing Tessellation` is forced.
* In order to help fine-tune tessellation precisely, initial tessellation parameters are stored for each mesh of the scene. When opening the `Tessellate` dialog box, parameters values are automatically adjusted to the selection's initial tessellation values, providing the selected parts share the same initial tessellation value. Otherwise, the `Medium` preset is automatically set, and a message is raised in the interface, in orange:

![Re-tessellate warning](/api/media?file=/asset-transformer-studio/2026.5.0/media/NewItem432.png)

## How to

To re-tessellate, follow these steps:

1. Select a [part](../glossary#part), or a selection of parts you wish to re-tessellate using the [Viewer](../../user-interface/window/viewer) or the [Product Structure](../../user-interface/window/product-structure-tree).
2. Open the `Re-Tessellate` dialog box:
   * From the [CAD](../../user-interface/menu-bar/cad-menu) menu
   * From the Re-Tessellate menu accessible from a right-click in the [Viewer](../../user-interface/window/viewer)
   * From the Inspector, using the `Re-Tessellate` button in the [Part component](../about-occurrences/occurrence-components#part-component)
3. In the `Tessellate` dialog box, change the tessellation parameters (see [About Tessellation](./_index.md) for more information about the parameters).
4. Click `Execute`.

![Re-tessellate in action](/api/media?file=/asset-transformer-studio/2026.5.0/media/ALGO_Retessellate_Large.gif)

## Messages

### Pre-process message box

Depending on the nature of the selection, and after clicking one of the `Re-Tessellate` actions, a first message box can be displayed before opening the `Tessellate` dialog box, asking you how to process parts that were already tessellated:

![Pre-process message](/api/media?file=/asset-transformer-studio/2026.5.0/media/ALGO_Retessellate-Preprocess-Message.jpg)

* `Re-tessellate`: All parts of the selection already tessellated before are re-tessellated, and non-tessellated parts are tessellated, with the parameters you define in the `Tessellate` dialog box.
* `Ignore`: Parts of the selection that are already tessellated are ignored: only non-tessellated parts are tessellated, with the parameters you define in the `Tessellate` dialog box.

### Warnings in the dialog box

Depending on the nature of the selection, a warning message can be displayed in the function dialog box, explaining how/if the selection is affected by the re-tessellation process.