- Model
- MacStep
- Type
- CAD viewer
- Reads
- STEP IGES STL 3MF
- Runs on
- macOS Win Linux
- Kernel
- Open CASCADE 7.9
- Exports
- PDF STL PNG
Free and open source
STEP in. Dimensioned drawing out.
MacStep opens STEP, IGES, STL and 3MF files. Orbit them, cut sections through them, measure them, then project a dimensioned ISO three-view and export the sheet as a PDF.
macOS · Windows · Linux — no installer required
What it does
Function / detail| View | Orbit, pan and zoom with a view cube and the seven standard views. Section planes cut on X, Y or Z with a live millimetre readout. |
|---|---|
| Measure | Point-to-point distance in the 3D view, snapping to vertices and edges so a click near a corner returns the corner rather than a point near it. |
| Assembly | The full tree with names and colours from the file. Show, hide, isolate, or dial any part's opacity; a Modified list tracks everything you changed. |
| Drawings | Exact hidden-line removal through Open CASCADE, laid out as an ISO 128 third-angle three-view with an isometric reference. |
| Dimensions | Linear dimensions from two picked points, and diameters from a single click on a circular edge. Placed clear of the geometry and of each other, and draggable when you disagree. |
| Export | PDF drawing sheet with an ISO 7200 title block, binary STL of whatever is visible, and PNG of the viewport. |
From solid to drawing
ISO 128 · ISO 129 · ISO 7200Most viewers stop at showing you the model. MacStep also produces the drawing: Front, Top and Right in third-angle projection at a shared scale, with hidden lines computed from the real B-rep rather than traced from a mesh.
Dimensions are placed by a solver that keeps the line and the value off the outline and out of each other's way, and widens the gaps between views to fit whatever it places. Drag any dimension and it follows the cursor over clear space, settling onto the nearest free row rather than landing on the drawing.
Drawings need STEP or IGES. STL and 3MF carry triangles only — there is no underlying geometry to project.
Third-angle arrangement, ISO 128
Get it
Latest release on GitHubLicence
GPL-3.0MacStep is released under the GPL-3.0. Use it at work, study it, change it, share it — no fee, no email, no permission needed. The one condition: if you pass it on, modified or not, on its own or inside something else, the source goes with it under the same licence.
Which is the point. Anyone can build on this; nobody can close it.
Geometry comes from Open CASCADE, which is LGPL-2.1. MacStep links it dynamically and ships it as separate libraries, so you can swap in your own build of it. Its source is available from the project above.