The Specifier

a design-specification tool

The Specifier is Khitchdee Design's under-development tool to specify a land-vehicle design-prototype.

1. It has a very simple user-interface based on "InterUnit-UI",
   that is being designed in conjunction with a land-vehicle prototype development process.
2. It uses a hexagonal-grid based virtual-protractor to specify angles and curves.

Specification

There are 2 aspects to the specification of a land-vehicle design.
1. A structural specification, which is 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 rider.
2. A construction-process specification, which specifies the construction-process of a design.
This is useful for an assembler or a fabricator. 
This will be implemented as a frame-by-frame visualisation of a dynamic model.

The Specifier is being created to specify bicycle related designs.
The specification process involves using the mouse and keyboard input to specify
3D objects on an orthographic 3D grid.

Visualisation

A specification could be visualised at any time using a separate Visualiser component.

The Visualiser will implement camera-perspective display-screen mapping of modelled 3D objects.
The camera will have location and orientation controls.
A single light source, at the same orientation and location as the camera,
will be used to illuminate the model to be displayed.

A 3D object will be represented as a set of 3D planar segments.
The Visualiser will map these 3D planar segments onto a 2D screen using 4-point plane-mapping.
Curved planes in 3D will be modelled as piece-wise jointed flat planes.
The rendering code will (initially) be based on the device's (2D) drawing engine.

The visualiser targets a per-frame visualisation time of 100ms
 to visualise a bicycle-model at 4K resolution on an iPhone 15 Pro class device.

Construction-process specification (planned)

We plan to produce a component for the specification of a construction-processes.
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 parts in the process
(such as components and tools).
They will then indicate transitions between states.
The construction-process specifier will use these construction states and transitions between them
to create a sequence of models to be visualised.
This sequence will be visualised using the Visualiser with some animation controls
(in addition to the Visualisers camera controls).

Photograph assisted specification (planned)

After the mouse and keyboard specification interface, we plan to produce an additional interface,
based on pictures of an under-development prototype and its components.
This will speed up the specification process.

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.

Bicycle Structural Overview

A bicycle is specified as:
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.

The attachments between the primary components to construct the bicycle.

1. Attachment specifications between all the parts of the bicycle.

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