Extract Geometry

Having a geometry file of an object is useful for testing geometry parameterizations or visualizing specific aspects of the geometry. For example, it can be helpful to prototype design variables on a simplified geometry before applying it to a complete mesh and case. Extracting a geometry is done through ParaView by importing the mesh, isolating the desired patches, and exporting the surfaces.

The extract geometry post-processing routine is available through both a command line executable and through the Python API. Using either method, the utility will read the mesh and write out the wall surfaces into a STL file.

Command Line

To call the utility from the command line, simply call the utility using the following command with the desired options:

usage: extract_geometry [-h] [-i INPUT_FILE] [-o OUTPUT_DIRECTORY]
                        [-p PATCHES [PATCHES ...]] [-ow OVERWRITE]

Named Arguments

-i, --input_file

Relative path to input file.

Default: ''

-o, --output_directory

Relative path to output directory. Default is ./

Default: './'

-p, --patches

Patches to include in the geometry file. Default is group/wall.

Default: 'group/wall'

-ow, --overwrite

Flag to overwrite existing temporary geometry and geometry files. Default is False.

Default: 'False'

Python API

To call the utility from Python, import the necessary modules and call the function with the necessary inputs:

postprocessing.paraview.geometry.extract_geometry(input_file=None, output_directory='./', patches='group/wall', overwrite='False')

Function to extract a geometry from an OpenFOAM mesh and write it as an STL.

Parameters:

input_filestr

Path to file to load with Paraview.

output_directorystr

Path to directory where the geometry files will be written. Default is “./”.

patchesstr or list

Patch name(s) to include in the geometry. Default is “group/wall”.

overwritestr

Flag to overwrite existing temporary geometry and geometry files. Default is False.