## On this page

  

 

 # assign\_mesh\_regions

 Last update: 02.04.2026 

<a id="ansys.meshing.prime.VolumeMeshTool.assign_mesh_regions"></a>

#### VolumeMeshTool.assign\_mesh\_regions(target\_part\_id, target\_cell\_zonelets, source\_part\_ids, small\_regions\_volume\_fraction)

Assigns a region id to the cells in target cell zonelets of target part id. The region id is based on their location within source part ids.

**Parameters:**

**target\_part\_id**

Id of the target part.

**target\_cell\_zonelets**

Ids of cell zonelets to be split into regions.

**source\_part\_ids**

Ids of solids used as a reference for assigning regions.

**small\_regions\_volume\_fraction**

Regions with volumes smaller than a specified fraction of the total volume are merged into their largest adjacent region. This helps to eliminate isolated cells and thin regions from the output.

**Returns:**

**[`VolumeMeshToolResults`](ansys.meshing.prime.VolumeMeshToolResults.md#ansys.meshing.prime.VolumeMeshToolResults)**

Returns the VolumeMeshToolResults.

**Return type:**

[`VolumeMeshToolResults`](ansys.meshing.prime.VolumeMeshToolResults.md#ansys.meshing.prime.VolumeMeshToolResults)

### Notes

**This is a beta API**. **The behavior and implementation may change in future**.

### Examples

```pycon
>>> results = volume_mesh_tool.AssignMeshRegions(target_part_id, target_cell_zonelets, source_part_ids, small_regions_volume_fraction)

```