Thumbnails (Preview) for 3mf, amf, obj, step, stl, x3d files

Install Workflow external scripts and create bash script to generate thumbnail for 3d models.

For generate thumbnail from obj, stl and x3d using minirender.
For 3mf, amf and step a temporary stl file is creating by PrusaSlicer.


  • Thumbnail generating when file adding or updating.
  • Thumbnail generating not immediately. Activating by cron.
  • Thumbnail generating for file less than set size.
  • Thumbnail not generating if png file already exist.


simple and nice solution.

With the File actions app files_scripts, you can solve that without an external bash script.
In addition, you can create a thumbnail at any time, but it can also be generated event-controlled via cron, as with workflow_script. Advantage with files_scripts: data such as cloud_data_path and occ_path are automatically recognized or not required.
If triggered via actions_script in the context menu, you could also adjust the values for tilt and yaw, depending on the object, which is an absolute added value in my opinion.
Con: You must learn lua script, but that is not too much of an effort


Replaced prusaslicer by gmsh to get support iges format.

sudo apt install gmsh

Could you maybe give us some pointers to tutorials or example code of how to do this?

I tried googling for other custom thumbnail generators but non of them seem to be using your approach?

Did you study the files_scripts App docs? You have to dive into it a bit and deal with lua script.

Let’s see, maybe if I feel like doing it in the next few days, then I’ll make you a small example, but I’m not promising anything, I’ve got a lot to do at the moment. But actually, everything is very well documented with the sample scripts that come with the app and the scripting API and manuals.


if i want to add the rule, i get configuration errors with %n and without.

I cant find the Problem, log is empty.



You have to select an event
es ist kein Ereignis ausgewählt

After the “Wenn” you have to select an option from the dropdown menu.

1 Like

Oh my god i,m so blind. i need holidays!!! thank you! :joy:


How can I install minirender ?
I tried but it’s seems don’t work for me…

Maybe I made a misstake…

My Workflow external scripts:

My minirender-master directory:

My (with chmod +x):

As far as I can see, your mistake is the variable minirender_path. You have:


but that is only the directory. The variable must point to the compiled binary, so in your case it has to be:


to make the magic happen

Much luck

@ernolf Thanks you for your reply but it doesnt work :pensive:

Did you try if the binary you compiled works (without the script)?