Papa’s Best STL-to-PNG converter

stltopng creates PNG images from STL files. It is built on the fastest STL viewer available, so it can generate hundreds of snapshots per minute when used from the command line.

Download

Requires my STL Thumbnails being installed!

Updated 5 August 2021 (changes, license).

Feel free to donate if you like my program!

stltopng.exe

for Windows 7 and later

Source Code

for use with your own projects

Quick Start

Drag and Drop

Drag and drop any STL file on stltopng.exe. This will generate a picture named stl.png in the same folder.

Command Line

To generate a picture of a file in ~1000×1000 pixels from the command line:

stltopng /res 1000 /png "X:\path\to\image.png" "Y:\path\to\design.stl"

Batch script

A Batch script to generate thumbnails in the size 256×256 pixels for all STL files in the current directory:

FOR /r %%i IN (*.stl) DO ( stltopng /res 256 /png "%%i.png" "%%i" )

What is this for?

For automation, mostly. Use it whenever you need to save pictures of STL files. For example:

If you have website where you provide your designs, you’re happy if you can let your server generate previews automatically!
One of my users wants their printer to display an image of the STL file that’s currently being printed, and stltopng comes in handy there.
If you use a customer management system that cannot handle 3D printing files natively, you can use stltopng to save images instead.
Of course it’s also a blessing if you just want to provide a catalog of your STL files for someone else!

Detailed Instructions

Supported operating systems are Windows 7 and later.

stltopng makes use of my STL Thumbnail generator, but stores the image in a file instead of passing it to Windows.

It runs from anywhere and needs no admin rights.

Usage: stltopng [options] <stl path>

/png <out path> – path of PNG to write; defaults to stl.png.
/res <pixels> – approximate sidelength of the PNG; defaults to 1024.

Returns zero if successful.

Status messages are printed to stdout; errors are printed to stderr.

Color and viewing angle

The background may be black unless you specifiy a background color. A fix is underway.

You can adjust the colors and the viewing angle via my STL thumbnail settings in the registry. I realize that’s cumbersome and it would be so much easier to pass these via command line, but an updated version is already in the works!