> For the complete documentation index, see [llms.txt](https://docs.ladybug.tools/butterfly-primer/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ladybug.tools/butterfly-primer/components/03_mesh/snappyhexmeshdict.md).

# snappyHexMeshDict

![](https://3867130239-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LPHXQ1CBjfLUuUW94tN%2F-LPHXSV32c4bM8DFZc3w%2F-LPHXa-x8Py7KbDSwIU1%2FsnappyHexMeshDict.png?generation=1540056855028097\&alt=media)

Set parameters for snappyHexMeshDict. Read more about snappyHexMeshDict here: <https://openfoamwiki.net/images/f/f0/Final-AndrewJacksonSlidesOFW7.pdf>

## Inputs

* **meshQuality \[Default]**

  Use 0-2 to auto generate the parameters for meshQualityControls
* **castellatedMesh \[Default]**

  Set to True to castellated mesh (default: True).
* **snap \[Default]**

  Set to True to snap mesh to the surfaces (default: True).
* **addLayers \[Default]**

  Set to True to push mesh away from surfaces and add layers (default: False).
* **nCellsBetweenLevels \[Default]**

  Script variable snappyHexMeshDict
* **maxGlobalCells \[Default]**

  An intger for the maximum number of global cells (default: 2000000).
* **surfaceFeatureLevel \[Default]**

  An integer for the extract features refinement. Default is None which

  means implicit meshing feature will be used.
* **expansionRatio \[Default]**

  Layers expansion ration (default: 1.1)
* **finalLayerThickness \[Default]**

  Thickness of final layer (default: 0.7)
* **minThickness \[Default]**

  Minimum thickness for layers (default: 0.1).
* **nLayerIter \[Default]**

  Overall max number of layer addition iterations. The mesher

  will exit if it reaches this number of iterations; possibly with an

  illegal mesh (default: 50).
* **additionalParameters \[Optional]**

  Additional parameters as a valid c++ dictionary. Additional values

  will overwrite the values from the other inputs above.

## Outputs

* **snappyHexMeshDict**

  Butterfly snappyHexMeshDict.

[Check Hydra Example Files for snappyHexMeshDict](https://hydrashare.github.io/hydra/index.html?keywords=Butterfly_snappyHexMeshDict)