We are producing, "The Specifier", an MCAD tool for specifying structural-assemblies. A structural-assembly is specified in terms of it's component parts and construction processes for connecting these parts. These processes can be implemented in an associated production facility called a Unit-construction-hub, also specified using The Specifier. Click on the link below to learn more about The Specifier.




The following is a review of MCAD tools commonly used by small and medium scale enterprises.

MCAD tools represent solid objects using parametric descriptions created using a "geometry-modeler". To visualise these solid objects on a 2D screen, they are represented by their 3D boundary surfaces (BREP). The ISO has standardised a format for BREPs and all tools support this format for interchange. For most industrial design projects, a 3D surface does not need to be edited directly. Common shapes are used and ther properties are controlled using the app. Sometimes, as in the case of specialised exterior sheet-metal design for an automobile, specialised tools are used to directly specify 3D surfaces. In addition head-mounted-displays, which offer a full 3D viewing experience are used for visualisation. Motion sensing sensors can be used to input shapes using hand movements. Hand-gesture based 3D surface input is a new direction that tools are starting to explore. Direct 3D surface design is still a process with a learning curve and its use is not very prevalent. Clay models continue to be used to create 3D surface designs, such as for automobile design.

From a designer's standpoint, MCAD tools are characterised by their geometry kernel. Examples of geometry kernels, currently in use, are Parasolid (Siemens), 3D ACIS Modeller (Spatial), ShapeManager (Autodesk), Granite (PTC), Convergence Geometric Modeller (Dassault), openNURBS (Rhino3D) and C3D (C3DLabs).


  • Platform: Windows or Cloud
  • Geometry Kernel: Parasolid
  • Launch date: 1995
  • Annual revenues (estimated): $1.5B
  • Location: MA, USA


  • Platform: Saas on Cloud
  • Geometry Kernel: Parasolid
  • Launch date: 2012
  • Annual revenues (estimated): $245M
  • Location: MA, USA

  • Platform: Windows, MacOS, Cloud
  • Geometry Kernel: ShapeManager
  • Launch date: 2013
  • Annual revenues (estimated): $20M
  • Location: CA, USA


  • Platform: Windows only
  • Geometry Kernel: Parasolid
  • Launch date: 1997
  • Annual revenues (estimated): $12.6M
  • Location: TX, USA

  • Platform: Windows only
  • Geometry Kernel: Parasolid or ACIS
  • Launch date: 2001
  • Annual revenues (estimated): $5M
  • Location: GA, USA



  • Niche: Ease of use
  • Platform: iPadOS + Pen, AppleVision Pro, Windows, MacOS
  • Geometry Kernel: Parasolid
  • Launch date: 2013
  • Annual revenues (estimated): $14.6M
  • Location: Hungary

  • Niche: HMD + hand-gesture based input
  • Platform: AppleVision Pro + NVidia CloudXR, Windows based HMDs
  • Geometry Kernel: C3D by C3DLabs
  • Launch date: 2025
  • Annual revenues (estimated): unknown
  • Location: Germany

  • Niche: NURBS based modelling
  • Platform: Windows, MacOS
  • Geometry Kernel: openNURBS
  • Launch date: 1998
  • Annual revenues (estimated): $13.1M
  • Location: WA, USA





The domain of MCAD has evolved since the first tools for 3D modeling and visualisation were introduced about 30 years ago. 2D CAD had been around for a long time. MCAD started with 3D.

Mechanical CAD tools require a mechanism for visualising 3D objects on a 2D display. We present a brief review of the underlying technology involved and how major MCAD tools use that technology.




A bicycle is specified as a primary frame and components, attachment mechanisms between them, and additional braking and gear-ratio control systems.

  1. The primary frame and components.
    1. A frame consisting of:
      • A head-tube, top-tube, down-tube and seat-tube.
      • A seat-stay and a chain-stay at the back.
      • A bottom bracket at the base of the frame.
      • Connectors that connect the parts in the frame.
    2. The front fork and handle-bar
    3. The chain-drive consisting of:
      a chain crank and pedals
      a freewheel
      a chain
    4. The front-wheel, front-wheel spindle and tire
    5. The rear-wheel, rear-wheel spindle and freewheel attachment, and tire.
  2. Attachment specifications between the primary frame and components.
  3. The braking system and optional gear-ratio control systems.
    1. A braking system and its attachment mechanism
    2. A gear-ratio control system and its attachment machanism