Transient STL File Conversion

Do you have a series of STL files which represent moving geometry? If this geometric motion is simple (constant rotation, or translation), you can utilize the “Rigid Body Motion” capability already in EnSight. However, what if the motion is complex, or if the STL surfaces change from timestep to timestep? The native STL file reader in EnSight expects steady state STL file information (either a single STL file, or multiple STL files via .xct; but still only for a single timestep).

A short Python routine can be used here to actually help out. This python routine takes a series of STL files, and assumes that they are part of a transient sequence, with one STL file per timestep. The Python routine converts the STL information into EnSight Case Gold format files, with multiple .geo files, allowing you to view your STL information in a transient nature. This routine can be further modified and customized to suit your needs, file conventions, or time information (since no time information is explicitly available within the .stl file).

Please feel free to contact CEI, or the author of the routine ( for further customization or questions.

To download this example Python utility, please click on the link below, and place into your User Defined Tools area.

Click here to download Multiple Transient STL Conversion Tool

Current Version : 1.0 (11-January-2013)

Current Limitations/Assumptions:

a. A series of ASCII stl files all with ‘.stl’ extension
b. Will convert and assume ALL “*.stl” files in the directory are to be converted.
c. All STL files have the same number of parts (but can change triangles from timestep to timestep)
d. Since there is no Time information with STL, will force Time 0 = 0.0 seconds, Time 1 = 1.0 seconds, etc
If user needs other time information, just change the time values in the .case file
e. STL files are all triangles (no quads)

Help Documentation can be found here :

LIGGGHTS and STL Transient Conversion Routine

liggghtsDo you have LIGGGHTS data that you’d like to visualize, analyze, or communicate? Do you have similar DEM (Discrete Element Model) type of data? EnSight can used easily to analyze, visualize, and communicate the results from a LIGGGHTS solution. In this particular situation, the user has both LIGGGHTS dataset for each timestep, along with STL data for each timestep which represents the moving geometry. This python routine converts both the LIGGGHTS data file as well as the STL data into EnSight format, allowing you to visualize both the moving geometry and particles at the same time, but also utilize the analysis capabilities within EnSight to quantify the discrete particle solution for such things as mass, center of gravity, particles & mass within a particular geometric region, amount of particles leaving the domain vs. time, etc.

Please visit this site for the up-to-date help and version information regarding this Conversion Routine:

The current release of this tool (version 1.6; 04-Dec-2012) can be downloaded with the following link. Simply place both files into your User Defined Tools directory, re-launch EnSight and start to visualize, analyze, and communicate your LIGGGHTS data within EnSight.

Click here to Download new version 1.6 of LIGGGHTS Conversion Tool