Note that this is beta, pre-release software. It may contain errors or inaccuracies and will not function as well as the final released software. If you have issues or ideas for improvements, feel free to open a discussion at Discord or contact via email.
Do not use the NVidia 430.86 / 431.36 drivers with beta 8! Due a driver regression, the Optix denoiser will crash.
The nightly build now uses Optix 7 which works on new drivers, but requires version 435.80 or newer.


Package OS Version Size Link
LibThree Core
The core application.
Windows 64-bit 1.0 beta8 32.0MB
LibThree Core
The core application.
Windows 32-bit 1.0 beta8 23.5MB
LibThree Core
The latest unofficial build.
Windows 64-bit nightly - 9/30 35.1MB
LibThree OpenCASCADE
OpenCASCADE module for LibThree, adding support for STEP, IGES and BREP files.
Windows 64-bit 9.25MB
LibThree Optix Denoiser (not required with the nightly build!)
Real-time AI denoising for NVIDIA video cards.
Requires GTX 650 or newer!
Windows 64-bit 6.0.0 172MB
LibThree Open Image Denoiser
AI denoising for any x64 processor.
Windows 64-bit 1.0.0 31MB
LibThree Textures
Collection of textures to get you started. If missing, the standard material library will not work!
OS independent 1.0 beta1 229MB
LibThree Blender addon
LibThree addon for exporting scenes from Blender
OS independent 1.0 beta1 0.1MB


The required free disk space for the installation is given in parentheses.
The installer will only create shortcuts, register supported file extensions and thumbnails in Windows Exporter, but otherwise the application is fully portable.
All installation packages can be optionally open and extracted manually via 7zip, WinRAR or similar software.
If you want to manually register the supported file extensions (without running the installer), run the following command (⊞ Win+R):
Windows 64-bit
Windows 32-bit
If you want to manually register thumbnails in Windows Explorer (without running the installer), run the following command (⊞ Win+R):
Windows 64-bit
Windows 32-bit
The main executable is called lib3, although advanced users have few more applications that can play with:
sceneconv is command line utility to import lib3 or third party formats and output lib3 or json files.
imageconv is command line utility to convert and process images.
denoiser is command line utility to denoise rendered images.
ior is command line utility to convert complex IOR tabulated data to artistic friendly base and tint color.
sysinfo is command line utility that can display system information.
lz4cli is command line utility that can work with LZ4 archives.


Run the following command (⊞ Win+R). Or just find and execute this file within Windows Explorer:
Windows 64-bit
Windows 32-bit
Delete the installation folder.

Sample Scenes

Daniel Kreuter Download: 3.6MB
Nikolay Tsys Download: 7.96MB
Hyperspace Madness Download: 20.2MB
Toon scene changes Download: 2KB
Michal Ahedov Download: 21.4MB
500 Group Download: 8.5MB
Bullet Physics Animation Download: 1.2MB
olmopotums Download: 11.3MB
Artem Tayurskii Download: 4.8MB
Manu Järvinen Download (blend): 21.4MB