RTSTRUCT/SEG to 3D polygon mesh conversion
Convert contour segments (RTSTRUCT) or label voxel grids (SEG) to 3D polygon meshes.
Problem
Radiation therapy structures (RTSTRUCT) and segmentation objects (SEG) encode anatomy as 2D contour slices or voxel label grids respectively. Downstream tools — surgical planning software, 3D printing pipelines, and visualisation platforms — require triangle-mesh geometry (STL, OBJ, GLTF). Converting these formats manually requires specialised toolchains and is error-prone without immediate visual feedback.
Steps
- Open a DICOM file (⌘O) — load an RTSTRUCT or SEG object alongside its reference image series.
- Open the 3D preview — click the 3D button in the top bar (or press ⌘3D) to open the mesh preview panel.
- Select structures — in the structure list on the left, toggle the structures or segments you want to include. Each structure renders as a coloured surface.
- Inspect the mesh — rotate, pan, and zoom the 3D viewport to verify geometry. Check that all contour slices are connected and no gaps appear between adjacent structures.
Result
Each selected structure or segment is converted to a closed triangle mesh and displayed as a 3D surface in the preview panel. Contour-based RTSTRUCT objects are triangulated via marching-cubes on a rasterised volume; voxel-label SEG objects are meshed directly. The resulting geometry is ready to export (see use case 5.8.2).