---
name: "freefoam-splitMeshRegions"
section: "1"
platform: "linux"
package: "freefoam"
version: "0.1.0+dfsg+1-3"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/freefoam-splitMeshRegions"
---

# freefoam-splitMeshRegions(1)

Splits mesh into multiple regions.

## NAME

freefoam-splitMeshRegions - Splits mesh into multiple regions.

## SYNOPSIS

**freefoam splitMeshRegions** \[-cellZones\] \[-help\] \[-makeCellZones\] \[-sloppyCellZones\] \[-blockedFaces *\<faceSet name\>*\] \[-largestOnly\] \[-srcDoc\] \[-doc\] \[-overwrite\] \[-insidePoint *\<point\>*\] \[-parallel\] \[-case *\<dir\>*\] \[-detectOnly\]

## DESCRIPTION

Each region is defined as a domain whose cells can all be reached by cell-face-cell walking without crossing - boundary faces - additional faces from faceset (-blockedFaces faceSet). - any face inbetween differing cellZones (-cellZones)

Output is: - volScalarField with regions as different scalars (-detectOnly) or - mesh with multiple regions or - mesh with cells put into cellZones (-makeCellZones)

## OPTIONS

- **-cellZones**

  Split different cell zones.

- **-detectOnly**

  Do no processing.

**-blockedFaces** *\<faceSet name\>*

Split at give face set.

- **-sloppyCellZones**

  Try to match regions to existing cell zones.

- **-makeCellZones**

  Create mesh with cells in different cell zones.

- **-overwrite**

  Overwrite existing data.

- **-case** *\<dir\>*

  Case directory.

- **-parallel**

  Run in parallel.

- **-help**

  Display help message.

- **-doc**

  Display Doxygen API documentation page for this application.

- **-srcDoc**

  Display Doxygen source documentation page for this application.

- **-insidePoint** *\<point\>*

  Only keep region containing specified point.

- **-largestOnly**

  Only keep largest region.

## NOTE

• cellZonesOnly does not do a walk and uses the cellZones only. Use this if you don’t mind having disconnected domains in a single region. This option requires all cells to be in one (and one only) cellZone.

• cellZonesFileOnly behaves like -cellZonesOnly but reads the cellZones from the specified file. This allows one to explicitly specify the region distribution and still have multiple cellZones per region.

• useCellZonesOnly does not do a walk and uses the cellZones only. Use this if you don’t mind having disconnected domains in a single region. This option requires all cells to be in one (and one only) cellZone.

• Should work in parallel. cellZones can differ on either side of processor boundaries in which case the faces get moved from processor patch to directMapped patch. Not very well tested.

• If a cell zone gets split into more than one region it can detect the largest matching region (-sloppyCellZones). This will accept any region that covers more than 50% of the zone. It has to be a subset so cannot have any cells in any other zone.

• writes maps like decomposePar back to original mesh:

• pointRegionAddressing : for every point in this region the point in the original mesh

• cellRegionAddressing : ,, cell ,, cell ,,

• faceRegionAddressing : ,, face ,, face in the original mesh + *turning index*. For a face in the same orientation this is the original facelabel+1, for a turned face this is -facelabel-1

## SEE ALSO

An overview of FreeFOAM is given in [**freefoam**(1)](/freefoam/1.md).

## AUTHOR

OpenCFD Ltd.

## FREEFOAM

Part of the [**freefoam**(1)](/freefoam/1.md) suite.

## COPYRIGHT

• Copyright © 2008-2012 Michael Wild.

• Copyright © 1991-2010 OpenCFD Ltd.