Chapter 10: EnSight Data Formats

This section describes the format for all readable and writable files in EnSight which you may need access to. The formats described are only for those files that are specific to EnSight. We do not describe data formats not developed by Ansys (for example, data formats for various analysis codes). For information about these formats, consult the applicable creator.


Note:  If you are using this documentation to produce your own data translator, please make sure that you follow the instructions exactly as specified. In many cases, EnSight reads data in blocks to improve performance. If the format is not followed, the calculations of how much to read for a block will be thrown off. EnSight does little in the way of error checking data files when they are read. In this respect, EnSight sacrifices robustness for performance.


Internationalization Support in EnSight File Formats

The EnSight application reads and writes a large number of file formats. Examples include the case gold data files, command language files, .xy plot files, and many others. Many of these formats were documented prior to the addition of internationalized text support in EnSight and therefore string encoding requirements have not been documented for them. In general, when the documentation does not specifically call out a text encoding scheme, the default platform encoding system, described here, is utilized.

When text strings appear in these files (for example, filenames, variable names, etc), EnSight assumes that these contains internationalized characters and interprets them as such. The specifics of support is a bit different on the various platforms. On the Linux and Mac platforms, the encoding system for all text strings in these files is UTF-8. One implication of this is that any use of extended ASCII character sets (for example, Latin-1) are not supported on those platforms. On the Windows platform, the encoding system is dictated by the local 8bit encoding system selected for non-Unicode applications (a system often referred to as MBCS). These Windows encoding systems tend to be language specific and a file written using one encoding system cannot be read unless using the same encoding system used to write it. For example, on Windows, if the MBCS encoding is set to Japanese and a command file containing Japanese characters is written, it cannot be played back on a Windows system where the MBCS encoding system is set to Western European.

EnSight will always write text strings (for example, in part names, variable names, command files) into files using the currently enabled text encoding system on the machine running EnSight. If the text strings are limited to the ASCII character set, they can be read by EnSight run on any other platform. If the text strings contain characters that require Unicode representation, they can only be read correctly in EnSight if the platform’s text encoding system is the same as the one that wrote the files.

EnSight Formats

EnSight has three evolutionary file formats listed below from oldest to most recent:

EnSight 5

- legacy format

- supported unstructured meshes only

- used a global nodal array

- used per node variables only

EnSight 6

- support for case file

- support for both unstructured and structured meshes

- uses a global nodal array

- use per node or per element variables

EnSight Case Gold (Recommended Format)

- is much faster than EnSight 6 and is more memory efficient (noticeable if you have a large number of parts or for larger models)

- uses connectivity which can be separate from the node ids

- uses a part basis rather than a global array

Format Illustration

EnSight Case GoldEnSight 6

part 1

node coordinates

element connectivity by local node index

part 2

node coordinates

element connectivity by local node index

...

part n

node coordinates

element connectivity by local node index

global nodal ids & coordinates

part 1

element connectivity by global node ids

part 2

element connectivity by global node ids

...

part n

element connectivity by global node ids

Jump to Detailed Description of Formats

Saving Gold from EnSight

EnSight can export your model into Case Gold format (either ASCII or Binary). Activate the variables of interest, select the parts in the main part window and then go to the File menu: FileSaveGeometric Entities.

Tool to Check EnSight Format

There is another advantage to using Case Gold format in that there is a debugging tool called ens_checker that can help you find mistakes in files as you write a translator or exporter. Each version of EnSight has an improved ens_checker with the version of EnSight as a suffix. For example with EnSight 2024 R2, use ens_checker. Just type ens_checker file.case and the code will echo its progress and the problems it finds to the console. This tool will also check EnSight 6 format.