stl2mask
Maintenance modeA command-line tool to convert mesh segmentations (STL, OBJ) to binary masks and back, for use in medical image processing pipelines.
About
stl2mask is a command-line tool that converts 3D mesh segmentations (STL, OBJ) to binary mask images (e.g. NIfTI, MHA) and back. Given a mesh and a reference image that defines the output image space, stl2mask builds a distance volume from the mesh and thresholds it to produce a binary mask; the reverse mask2stl command turns a binary mask back into a mesh using the Marching Cubes algorithm.
The tool grew out of the need to move tumour and organ delineations between mesh-based modelling tools, such as OPT Tumour Models, and the voxel-based image formats used in treatment planning systems, without manually re-implementing this conversion for every project. It is installed as a standalone CLI via pipx or uv tool install, so it can be used independently of any particular Python environment.