A polyline is a geometric object made of connected line segments. It is defined by an ordered set of points (vertices), and each segment connects two consecutive points, forming a path in 3D space. In MeshInspector, polylines hold cross-sections, contours, isolines and paths; the tools for them are on the Lines tab.
Unlike meshes, polylines do not form surfaces. Unlike point clouds, they connect their points, so they have a clear linear structure.
Polylines are characterized by:
- An ordered sequence of vertices.
- Connectivity between consecutive points (edges).
- A structure defined by line segments rather than surfaces or volumes.
- A measurable length along the path.
Polylines in MeshInspector
When you open or create a polyline, it appears in the Scene tree and in the viewport as connected lines. In the Scene tree, its icon is three slanted lines.
Two panels below the Scene tree describe the selected polyline:
- Information shows Object Type (Polyline), the size of the bounding box, the numbers of Vertices and Edges, the total Length, the Avg Edge Length and the number of Components (separate lines in the object).
- Transform lets you scale, rotate and move the polyline in 3D space.
On the Inspect tab, Object Info shows general information about the selected polyline, such as the number of vertices and edges, the total length and the bounding box. For element-level data, open Lines › Lines Info (Professional plan): it shows the vertices and edges with their IDs and connections, and lets you step from one element to the next. Both panels can be open at the same time.
Where polylines come from
| Source | Tool | Plan |
|---|---|---|
| Cross-section of a mesh | Inspect › Section | Free |
| Points in order | Points › Points to Lines, Lines › To Spline | Free |
| Distance map isolines | Distance Maps › Distance Map to IsoLines | Professional |
| A CNC program | Toolpath › G-code to Lines | Professional |
| Text | Mesh Edit › Create Text | Free |
Section cuts objects with a plane and can create a polyline from the cut, for example to measure a profile or to export it as DXF. Create Text can make text as a mesh or as lines.
Open a polyline
Open a file with Home › Open Files or drag it into the window. These formats open as a polyline:
| Format | Open | Export |
|---|---|---|
| MRLINES | Yes | Yes |
| PTS | Yes | Yes |
| PLY | Yes | Yes |
| SVG | Yes | No |
A PLY file opens as a polyline when it has vertices and edges but no triangles. Export of a polyline can also write DXF, a format that many CAD, laser and CNC programs read. The full list of formats is in Supported File Formats.
What you can do with a polyline
| Task | Tools on the Lines tab |
|---|---|
| Change direction | Flip Orientation |
| Fewer or more points | Simplify, Subdivide (Professional) |
| Smooth | Reduce Noise |
| Split or join | To Components, Combine |
| Analyze | Lines Info, Lines Derivative (Professional) |
Convert a polyline to another type
| Result | Tool | Plan |
|---|---|---|
| Mesh from closed lines | Lines › Lines to Mesh | Professional |
| Mesh around the lines | Lines › Offset | Professional |
| Mesh along a path | Lines › Extrusion Body | Free |
| Point cloud | Lines › Lines to Points | Professional |
| Voxel volume | Lines › Lines to Voxels | Free |
| Distance map | Lines › Lines to Distance Map | Professional |
| Tool swept volume | Toolpath › Swept Volume | Free |
Extrusion Body sweeps one polyline along another. Swept Volume builds the space a milling tool occupies along the polyline, as for a G-code toolpath.
Save a polyline
- Export saves the selected polylines as .mrlines, .pts, .ply or .dxf.
- Home › Save Scene saves the whole scene to a MeshInspector scene file (.mru).
Polyline options in the Scene tree
Right-click the polyline in the Scene tree to change how it is displayed: points, dashed lines, smooth corners, line width, point size, colors and opacity. The menu also has the Remove and Clone buttons. Every option is explained in Scene Tree Mastery.
