SMILI (Simple Medical Imaging Library Interface, pronounced “smilie”) is a free, open-source framework for building biomedical imaging applications, and its viewer sMILX gives researchers and students a drag-and-drop way to look at medical images and 3D surface models. It is built on Qt, ITK and VTK, and the current release, 2.0 Full from June 2025, ships ready-made installers for Windows, macOS and Ubuntu Linux.
SMILI is a general research tool with no dental features and no dental documentation. What makes it useful around a dental school or lab is simple: sMILX can open image volumes and surface meshes (including STL and PLY), overlay labels and models on images, and clean, smooth or decimate a mesh without writing code, with a Python console for anyone who wants to automate it.
SMILI at a glance
| Item | Details |
|---|---|
| Latest version | 2.0 Full (24 June 2025); a 2.1 Alpha pre-release followed in October 2025 |
| Licence | Free and open source, BSD-style licence from CSIRO (Australia) |
| Platforms | Windows (installer, Qt 6 installer and a portable build), macOS (.dmg), Ubuntu 22.04 (.deb) |
| Developer | Shekhar S. Chandra and co-authors; code copyright CSIRO |
| Official website | github.com/shakes76/smili (project homepage on smili-project.sourceforge.io) |
| Best for | Researchers and students who want a light viewer for images and surface models, or a quick base for their own imaging tools |
What it does
- sMILX viewer: open images and models by drag and drop, with right-click menus for most operations.
- Overlay surface models, label maps and images in the same view.
- Read surface models in VTK, OBJ, PLY and STL formats and save them as VTK, PLY or STL.
- Surface processing: clean, smooth (windowed sinc), decimate, apply colour maps and change views.
- Create animations and contours from models and surfaces.
- Plugins for Python scripting (with a console that automates the interface), animation and movie making, DICOM and statistical shape models.
- Command-line applications and batch scripts, for example for overlays, so the same steps can run over many files.
- C++ libraries with and without a user interface, so developers can reuse SMILI code in their own programs.
How dental teams use it
These are general sMILX features applied to dental research data; SMILI itself has no tooth, implant or orthodontic tools and is not a diagnostic product.
Check a printed or scanned model
- Drag an STL or PLY file of a model or intraoral scan into sMILX.
- Rotate and inspect the surface, then use the surface operations to clean it.
- Smooth or decimate the mesh if it is too heavy, then save it as STL or PLY.
Overlay a segmentation on a scan
- Open the anonymised image volume.
- Drag the label map or surface model produced by your segmentation onto the same window.
- Review the overlay slice by slice to see whether the segmentation follows the anatomy.
Batch-process a set of models
- Open the Python console in sMILX or use the batch scripts in the source repository.
- Loop over a folder of meshes, applying the same smoothing and decimation.
- Save each result under a consistent name for your study.
Install and first run
- Windows: run the 2.0 Full setup program, or the Qt 6 variant; a stand-alone build that runs without installation is also published.
- macOS: install from the .dmg. macOS may report the app as damaged because it came from the internet; the developers’ fix is to run
sudo xattr -cr /Applications/smilx.appin Terminal after installing. - Linux: install the Ubuntu 22.04 .deb package; other distributions need a source build.
- Building from source: CMake plus Qt, VTK and ITK. Version 2.0 supports Qt 5.15 or Qt 6, VTK 8 or 9, and builds with Visual Studio 2019 or 2022 on Windows.
- Learning: the project’s Quick Start page and YouTube channel show the drag-and-drop workflows with short videos.
Limitations
- No dental features and no dental examples in the official documentation.
- Documentation is thin: much of it is the README, release notes and videos.
- Small developer team; the 2.1 version is still an alpha pre-release.
- Linux packages only for Ubuntu 22.04; no iOS or Android version exists.
- Not a medical device and not intended for diagnosis.
SMILI vs alternatives
For research-grade processing with a larger feature set, medInria adds registration, filtering and a patient database. For heavier mesh editing, OpenFlipper is a stronger choice. Developers who outgrow SMILI can work directly with ITK and VTK, the libraries it wraps. For quick volume viewing only, Mango is lighter.
FAQ
Is there a SMILI download for Mac?
Yes. Version 2.0 Full includes a macOS .dmg installer. If macOS says the app is damaged, clear the quarantine flag with the xattr command given by the developers.
Is SMILI free?
Yes. SMILI is free and open source under a BSD-style licence from CSIRO.
What is sMILX?
sMILX is the SMILI viewer application: the program you actually run to open images and surface models. SMILI is the name of the whole framework and its libraries.
Can SMILI open STL files?
Yes. sMILX reads STL, PLY, OBJ and VTK surface models and can save them as STL, PLY or VTK.
Does SMILI have dental tools?
No. It is a general biomedical imaging framework; any dental use is done with its general viewing and mesh tools.
What is a good SMILI alternative?
medInria is the closest free research viewer with more processing features. Developers can also build directly on ITK and VTK.
Last checked against official sources: 29 September 2026 (developer website: github.com). Versions and licence terms change — confirm on the developer's site before deploying in a clinic.
