Extract thumbnail images from 3MF files and display them in file managers.
Preview images are great. As .3mf is supposed to be the universal 3D Printing standard, and adoption is expected to be rapid, we should be able to see embedded thumbnail image previews for them in file managers like pcmanfm, nautilus, or even Windows explorer.
git clone https://github.com/themanyone/3mfthumb.git
cd 3mfthumb
Fedora, Centos.
dnf install libzip-devel lib3mf-devel zlib-ng-devel
Ubuntu, Debian.
apt install libzip-dev lib3mf-dev zlib1g-dev
Arch
pacman -S libzip lib3mf zlib1g
We will assume a GNU build environment with tools like gcc-c++, pkg-config and make.
make
make install
Multi-user environments. Please do not use sudo make install unless the system has
multiple graphical desktop users. In that case, you may edit Makefile to change DESTDIR
to INSTALL_ROOT. And manually remove old thumbnails for each user:
rm -rf $HOME/.cache/thumbnails/*
Previews typically work after this. If not, log out of the desktop session (or reboot).
Don't forget to configure file manager preferences to show previews for files > 1MB.
make uninstall to remove these components if no longer needed.
The current version of the Lib3MF API uses the lib3mf_implicit.hpp
header file instead of Lib3MF_Resources.hpp. Available from the
3MF SDK, this newer API provides a
simplified interface for working with the Lib3MF library. If installed in a
different place, you can use the updatedb and locate commands to find it.
This code employs the CWrapper::loadLibrary() method to load the Lib3MF library and create a
new model. It then uses the QueryReader() method to create a new reader for the 3MF file
format and read the model from a file using ReadFromFile(). Finally, we query the
HasPackageThumbnailAttachment() and GetPackageThumbnailAttachment() methods to retrieve the thumbnail
attachment and write it to a file using WriteToFile().
The Makefile uses pkg-config --cflags --libs lib3mf to obtain the compiler flags to use. In particular, the location of lib3mf_implicit.hpp. If for some reason your system does not have pkg-config, you might be able to substitute these into the Makefile.
BUILD_CFLAGS:=-I/usr/include/lib3mf
LDFLAGS:=-l3mf -lzip -lz
On Arch, lib3mf-dev may not be properly installed. The build script forgot to create simlinks to the C bindings. It should be filed as a bug. A command such as th following might work around the issue.
ln -s /usr/include/lib3mf/Bindings/Cpp/* /usr/include/lib3mf/
Using lib3mf_sdk
If it stubbornly refuses to build using the distro-provided packages, install zlib and libzip, or make sure their development libraries are installed. Then get the SDK.
cd #3mfthumb src dir
wget https://github.com/3MFConsortium/lib3mf/releases/download/v2.4.1/lib3mf_sdk_v2.4.1.zip
unzip lib3mf_sdk*
Now we can build 3mfthumb
make CFLAGS=-I./lib3mf_sdk/Bindings/Cpp LDFLAGS="-l3mf -lzip -lz -L./lib3mf_sdk/Lib"
To build Windows executable on Linux system, Use
the distro's package manager to install mingw64-gcc-g++, mingw64-zlib, and
mingw64-libzip. Now we need the lib3mf.dll, available from the above SDK download.
Now use mingw64-make to build the windows executable, 3mfthumb.exe. Set LIBS to the location of the extracted lib3mf/Lib dir, which should already contain a precompiled library lib3mf.dll.
mingw64-env #important!
mingw64-make CFLAGS=-I./lib3mf_sdk/Bindings/Cpp LDFLAGS="-l3mf -lzip -lz -L./lib3mf_sdk/Lib"
Copy 3mfthumb.exe along with lib3mf.dll to somewhere on the Windows machine. Maybe in C:\Program Files
In theory, we can use regedit to designate 3mfthumb.exe as the preferred handler to generate image previews for .3mf files. ChatGPT suggested something similar to the following. If it doesn't work, you can ask ChatGPT or Bing to fix it up.
- Open the Registry Editor by typing "regedit" in the Windows search bar and selecting "Registry Editor".
- Navigate to HKEY_CLASSES_ROOT.3mf.
- Right-click on something like "ThumbnailHandler" and select "Modify".
- Set the value data to the full path of 3mfthumb.exe (e.g. "C:\Program Files\3mfthumb.exe") and click "OK".
- Close the Registry Editor.
If it works, when you navigate to a folder containing a .3mf file, Windows should generate a thumbnail using 3mfthumb.exe.
Kubuntu thumbnailer commands work, but nautilus fails to genereate ...
Try (re)installing ffmpegthumbnailer. After that, the system might be configured to show thumbnails, since this topic has generated a lot of discussion. Then again.
rm -rf $HOME/.cache/thumbnails/*
Due to budget and time constraints, image previews have not been tested on Windows yet. But we're working on it. Discuss issues on the GitHub issue tracker.
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