Skip to main content

Visualizing outputs

Converting output to VTK format

To convert the binary output files to VTU files, run

2vtk.py modelname

modelname should be the one defined in the config file.

To see full usage information (including options for marker data VTP files), run

2vtk.py -h

The processed VTU (node and cell data) and VTP (marker data) files can be visualized with ParaView or VisIt.

Some outputs can be disabled by editing 2vtk.py and output.cxx.

VTKHDF output format

DES3D can write output in the VTKHDF format (.vtkhdf), a self-contained HDF5-based format supported by ParaView 5.11+. VTKHDF files bundle all time steps into a single file, making them easier to manage for long runs than the equivalent per-step VTU collection.

Updating an existing VTKHDF file

The -u / --update-vtkhdf flag lets you add or recompute derived fields (e.g., strain-rate invariants, second invariant of stress) in an existing .vtkhdf file without regenerating it from scratch. This is useful when you want to add a newly supported output quantity to a completed run.

2vtk.py --update-vtkhdf modelname.vtkhdf

Requirements: h5py must be installed (pip install h5py or conda install h5py).

Safety: The update is performed in-place. Back up your file before running if it is large or irreplaceable. The script prints a warning and exits if the target file does not look like a valid VTKHDF file.

HDF5 file locking

On some parallel or network filesystems, HDF5 file locking can cause a BlockingIOError. DES3D disables HDF5 locking automatically when writing VTKHDF output. If you encounter this error when running 2vtk.py externally, set HDF5_USE_FILE_LOCKING=FALSE in your environment.