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Display displacement

This script visualizes displacement fields from a gcrack simulation and saves them as a series of images.

Description

The script reads displacement data, applies potential transformations (warping), and saves the resulting image at each load step.

Usage

To visualize the displacement fields, run the following command in the results_<name> directory:

gcrack_displacement_plotter

This command generates one image file per load step.

Arguments

You can pass different arguments to the script. For detailed information on available options, use:

gcrack_displacement_plotter --help

Creating a Video Animation

The generated images can be used to create a video animation of the simulation. Here's an example using ffmpeg:

ffmpeg -framerate 25 -pattern_type glob -i 'Displacement*.png' Displacement.mp4

export_displacement_figures(factor, extension)

Export the displacement fields into image files.

Attributes:

Name Type Description
factor float

Amplitude of the displacement warping.
extension str

Extension of the image file (e.g., "jpg", "png").
Source code in src/gcrack/tools/display_displacement.py 
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def export_displacement_figures(factor: float, extension: str):
    """Export the displacement fields into image files.

    Attributes:
        factor (float): Amplitude of the displacement warping.
        extension (str): Extension of the image file (e.g., `"jpg"`, `"png"`).
    """

    # Find the pvtu files
    pvtu_files = list(sorted(Path(".").glob("Displacement*.pvtu")))

    # Create a plotter
    pl = pv.Plotter(off_screen=True)

    # Read each pvtu file
    for t, pvtu_file in enumerate(pvtu_files, start=1):
        # Read the file
        data = pv.read(pvtu_file)
        # Warp by displacement
        data = data.warp_by_vector("Displacement", factor=factor)
        # Display the results
        pl.add_mesh(data, scalars="Displacement")
        pl.view_xy()
        # Keep a constant camera position
        if t == 1:
            cpos = pl.camera_position

        pl.camera_position = cpos
        # Add frame to the gif
        pl.show(screenshot=f"Displacement_{t:04d}.{extension}", auto_close=False)
        # Clear the plot
        pl.clear()
    # Close the plotter
    pl.close()

main()

Entry point of gcrack_displacement_plotter.

Source code in src/gcrack/tools/display_displacement.py 
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def main():
    """Entry point of `gcrack_displacement_plotter`."""
    # Create the parser
    parser = argparse.ArgumentParser(
        prog="gcrack_displacement_plotter",
        description="Generate the displacement field images from a gcrack simulation",
    )
    parser.add_argument(
        "-e",
        "--extension",
        help="extension of the figures (see matplotlib.pypyplot.savefig)",
        default="png",
        type=str,
    )
    parser.add_argument(
        "-f",
        "--factor",
        help="scaling factor (0.0 for no warping)",
        default=0.0,
        type=float,
    )

    # Parse and extract the arguments
    args = parser.parse_args()
    factor = args.factor
    extension = args.extension

    # Generate the figures
    export_displacement_figures(factor, extension)