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Visualization Using ParaView

ParaView State Files for Time-Domain Simulations

ParaView can save state files, which can then be loaded later. This is an easy way to apply the same template (glyphs, colors, scaling, etc.) to similar datasets.

Creating ParaView state files

When you have created a particular view in ParaView that you would like to save as a template for other OpenFAST simulations, click File -> Save State ... and choose a location and name for the file.

Using ParaView state files

To use a state file:

  1. Run OpenFAST with the appropriate modules and VTK inputs (WrVTK, VTK_type, VTK_fields) set for the template ParaView state file you want to use. For the easiest use of ParaView state files, the name of the OpenFAST input file should have the same base name as the file used in the template.

  2. Open ParaView, click File -> Load State ... and then select the appropriate .pvsm file.

    • ParaView stores state files with absolute paths, so you will need to tell it the directory where the state data files are located. Choose Search files under specified directory in the Load State Options window, and then specify the directory where OpenFAST wrote the .vtp files. Typically this is the <OutPath>/vtk/ directory.

  3. Tips

    • Make sure you have a version of ParaView newer than May 2017 so that the Load State Options window is available. Otherwise you will have to manually set the path for each file ParaView reads.
    • Note that state files load on top of whatever is open in ParaView, so if you load the state file twice, you will get two copies of all the files.
    • If your simulation generates files at more output times than were used in the state file, you can reload the files using File -> Reload. There should be an option that says This reader supports file series. Do you want to look for new files in the series and load those, or reload the existing files? Choose Find new files.
    • Most of the VTK data OpenFAST outputs are "Unstructured Grid" datasets.

Visualization of Mode Shapes

Note: These steps are followed in the Matlab script AnalyzeModeShapes.m contained in this directory.

To visualize mode shapes:

  1. Run OpenFAST for linearization analysis (Linearize = true) with WrVTK = 3. Note that if you would like to visualize the orientations, you should also set VTK_fields = true and VTK_fps to a value large enough to capture the motion of the mode shapes with the highest natural frequencies.
   OpenFAST.exe 5MW_Land_ModeShapes.fst
  1. Run MBC3 analysis in Matlab. This will write a file named ModesVizName (a string set by the user). Note that this requires the matlab-toolbox repository:
    MBC_data = fx_mbc3( LinFileNames, ModesVizName );
  1. Run OpenFAST with the visualization input file:
   OpenFAST.exe -VTKLin ElastoDyn-Modes.viz
  1. Run ParaView to view the mode shapes. You can either open the state file ED_Surfaces.pvsm inside ParaView, or you can use the included Python script to generate avi files of the mode shapes. See Creating animations of the mode shapes

Creating animations of the mode shapes

To create animations of the mode shapes

  • Manually
    1. Open the mode-shape state file, ED_Surfaces.pvsm, using the instructions from the time-domain section of this document.
    2. If necessary, select each mesh and reload the files (File -> Reload Files or F5), selecting the option to search for new files.
    3. Select File -> Save Animation.
      • Type in a name for the animation file, and select the type of file to generate. Press OK.
      • In the "Save Animation Options" window that pops up, select Save all views, and set the Frame Rate that was used when you generated the vtk files in OpenFAST (check the summary file for the exact value used). Press OK.
  • Using Python with ParaView
    1. Add ParaView's bin directory to your path. For example, on my Windows machine, I type:
   set path=C:\Program Files\ParaView 5.7.0-Windows-Python3.7-msvc2015-64bit\bin;%path%

  You will need to modify this if you have a different version of ParaView or have installed it in a different directory.
  1. Open plotModeShapes.py, and edit variables at the top:
    • mainDirName is the name of the directory where the mode-shape vtk (.vtp) files are stored
    • fileRootFmt contains a format specifier for the root name of the .vtp files, excluding the mesh name. Use {:d} in place of the mode number.
    • nModes is the number of modes to visualize (starts sequentially from mode 1)
    • fps is the number of frames per second that the vtk files were generated with (see the FAST summary file for the exact value) Note: The current version of ParaView seems to ignore the frame rate that is specified when saving the animation.
    • StructureModule is a string indicating the abbreviation of the structural model being used. This should be "ED" when ElastoDyn is used, or "BD" when BeamDyn is used.
  2. Run ParaView Python:
   pvpython plotModeShapes.py

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