EnSight version 10.1.x and below contains a VTK Beta reader, that by default is not exposed to the user.
This Beta version of the reader has been developed and improved, so that EnSight version 10.2.1(b) and newer contains a VTK reader, by default visible to the user. EnSight 10.2 utilizes the VTK-7.0 Library.
The VTK format is a collection of multiple file extensions, each one of which has a different role.
Supported File Extensions:
The reader accepts VTM, VTU, VTS, ad VTK file format extensions.
VTK denotes the simple legacy format file.
VTU denotes a Serial Unstructured Grid format information for the XML-based syntax.
VTS denotes a Serial Structured Grid format information for the XML-based syntax.
VTM denotes a Multi-Block file information (see further information below).
The VTM extension
VTM files are VTK Multi-block files.
Assume that a user is running a simulation using any solver in a parallel mode where mesh is distributed among "N" compute nodes. Each compute node will write its own set of data ( mesh + variables ), which means the user will have "N" .vtk/.vtu/.vts files. And each of this file is a separate link in a VTM file.
Files written in any of these formats using parallel solver can be loaded at once using ".vtm" file, as the VTM file can point to multiple but different .vtk / .vts/ .vtu files written by each compute node of a parallel solver. But, still these files follow rules meant to write serial VTK files.
Parallel VTK format
VTK parallel files (.pvtk, .pvtu, .pvts) contains some extra information specific to parallel mode. This file format is currently not supported by EnSight's VTK reader.
Known Restrictions/Caveats in the Reader
The VTK reader does not yet handle polyhedral elements. During the reader process, these elements will be skipped, while non-polyhedral elements will be read in. This may appear to the user like "holes" in the parts (missing polyhedral elements).
The VTK reader does not yet support polydata (.vtp) or rectilinear grid (.vtr) file formats.