Specifier 1.0: differentiating features

In addition to its use of a hex-grid for curve and surface specification, Specifier 1.0 targets new design and prototyping, and fits more efficiently into a design-prototyping process than any existing tool. It is not a full-featured tool (such as Solidworks) meant for a factory or large scale industrial production use.

Licensing

Khitchdee Design () plans to license the Specifier to industrial-designers and prototype developers. We also plan to license the Specifier's hex-grid based geometry modeller to other MCAD tool vendors.

Competition: A review of current MCAD tools

Current 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).

For new product designs associated with prototyping or small-scale production processes, the following MCAD tools are commonly used.

The most commonly used tool

Cloud-based collaboration enabled tools for smaller scale industrial-design

Established MCAD tools for industrial-design targeting small-scale manufacturing

Niche MCAD tools (ease-of-use and NURBS based modeling)

MCAD related articles

What is design-specification?

There are 2 aspects to the specification of a land-vehicle design.

1. A structural specification.
   A static description of the built up structure of a design.
   It includes a specification of each part in a design,
   how the parts connect with each other,
   and a structural model of the user (if applicable).
   
2. A construction-process specification.
   Specifies the construction-process of a design.
   How each component in the design is contructed
   and how the components are put together to produce the design.
   This is useful for an assembler or a fabricator.
   

What is specification visualisation?

A (design-specification) Visualiser implements perspective-correct display-screen mapping of modelled 3D objects.
Our visualiser models a camera with a location and orientation,
and a single light source, at the same orientation and location as the camera.

We represent a 3D object as its outer surface,
a lattice of 3D planar segments.
We map these 3D planar segments onto a 2D screen using 4-point plane-mapping.
A curved plane (in 3D) is modelled as a lattice of flat planes.
Our visualiser uses only the device's (2D) drawing engine,
and targets a visualisation time of 100ms/frame
for a bicycle-model at 4K resolution on an Snapdragon 8 Gen 5 SOC class device.

Construction-process specification in the Specifier (planned)

We plan to produce a construction-processes specification component
after the structural specification component.
The designer will identify several construction states in the construction process.
Each construction state will be a physical model of the relative placement of the components and tools in the process.
The designer will indicate transitions between construction states.
The construction-process specifier will use these construction states and transitions between them
to create an interpolated sequence of models to be visualised.
This sequence will be visualised using the Visualiser with some animation controls.

Photograph assisted specification in the Specifier (planned)

After the mouse and keyboard specification interface,
we plan to produce an additional interface to improve structural specification input efficiency.
This interface will work as follows:

1. A designer loads photographs of a real object into the app
   (with a description of the approximate camera parameters used in taking those photographs).
2. Identifies (in terms of 2D point descriptions) the components in the structure of the object in the photograph.
3. For each component, they describe its 3D orientation and size, based on physical measurements.

Structural overview of a bicycle

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

A. 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.

B. Attachment specifications between the primary frame and components.

C. 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