OpenShape3D is openly inspired by Shapr3D — same modeling philosophy, same gestures, same "CAD should feel native on a tablet" conviction. So how do they actually compare? Here's the honest version, from the OpenShape3D side.
Where they're the same
- Direct modeling workflow: sketch on any plane or face, tap a fill and pull it into a solid, push/pull faces with automatic union/subtract, drag-to-fillet edges.
- Real B-rep kernels: Shapr3D runs Parasolid; OpenShape3D runs OpenCASCADE. Both produce exact, watertight, manufacturable solids — not meshes.
- Sketching with constraints: both offer geometric constraints and driving dimensions with a live solver.
- Touch + Pencil first: one-finger orbit, two-finger pan, pinch zoom, Pencil drawing.
Where Shapr3D is ahead
Credit where due — Shapr3D is a mature commercial product with a large team:
- Parametric history mode layered on direct editing.
- 2D drawings with dimensions and tolerances.
- Photorealistic visualization and configurable materials/scenes.
- STEP/IGES and broad professional format support, sync across devices, and commercial support.
- macOS and Windows versions alongside iPad.
Where OpenShape3D is different (and sometimes ahead)
- Price: free. No subscription, no feature-gated tiers, no account, no sign-in.
- Open source: the entire app — SwiftUI, custom Metal renderer, pure-Swift constraint solver, OCCT integration — is readable and forkable on GitHub. If a behavior bugs you, you can fix it.
- Privacy: projects live on your device; nothing uploads (see our privacy policy).
- iPhone: the full toolset runs on iPhone, not just iPad.
- Already covered: constraints & dimensions with DOF feedback, revolve/sweep/loft/helix, booleans, linear & circular patterns, split body, mirror/scale/align transforms, section views, display modes (shaded, wireframe with true hidden-line, x-ray), materials, measure, and STL/OBJ/3MF/GLB/USDZ/DXF export with STL/DXF/image import.
Current OpenShape3D limitations
Honesty matters in an open project: there's no parametric history sidebar yet, no 2D drawing sheets, and no STEP/IGES exchange (the OCCT data-exchange modules are large; it's on the roadmap). Fillets and complex booleans are as good as OCCT — excellent, though Parasolid remains the industry benchmark for edge cases.
The bottom line
| Choose | If |
|---|---|
| Shapr3D | You need drawings, STEP, parametric history, or vendor support — and the subscription fits your budget. |
| OpenShape3D | You want capable, exact, private solid modeling on iPad/iPhone for free — for learning, hobby engineering, 3D printing, and hacking on the tool itself. |
Plenty of people will sensibly use both. And since OpenShape3D costs nothing to try, the comparison is cheap to run yourself.