CAD-DX: a format to store information and data - Informational

[sshahabCX]

In this document, I shall describe an other aspect of CAD (Computer-Aided design). Unlike the common view, CAD as a Design Drawing that only represents objects. CAD store information and data about the objects in a hierarchical fashion.

We will leverage the abilities of data-analysis-algorithms to extract and manipulate the CAD hierarchical information and generate values for our clients business challenges.

Introduction

CAD files contain metadata range from basic geometries, abstract geometries and the entire objects geometries. CAD data and information contain underlying relationships between the data points which govern by the continuity theorem and the rule of analytical geometry and formats can be ASCII or binary.

The data points and the relationships can be preserved and sharable among different software and tools. Even they can be extracted to XML and other formats being fed into any data-analytical-algorithms for further processes and manipulations to help designers and manufacturers improve products and processes, The outputs can be fed back and being embedded to the original objects.

2D CAD files include all dimensions, notes, sections, and can also include GD&T (Geometric Dimensioning and Tolerancing). It is worth noting that this has long become a standard way of working for many users of CAD tools .

The generation of the parametric 3D model made it possible to quickly and semi-automatically generate orthographic and isometric drawing views, and the detailed information was added to the drawings. The problem with this hybrid 2D & 3D approach is that if the 2D drawing is not tied to the 3D geometry, the two can become out of sync; the part can be updated, yet the drawing still reflects older information, or vice versa. This can also happen with CAD systems that have part-drawing associativity if the associativity is lost, or if the CAD data is translated to another format (which destroys associativity).

3D CAD Metadata

3D metadata consist of meshed geometry, surface geometry, solid geometry, model based design (MBD), Product and Manufacturing Information (PMI) and user-defined attributes, or some combination of them.

3D CAD Metadata Hierarchy

3D CAD metadata have a hierarchical structure. This hierarchy allows us to extract list of parts an physical properties of the main objects and the objects' parts. The metadata include PMI data and user defined data.

ASCII vs Binary CAD Data

Several CAD formats such as ACIS can be ascii or binary. ASCII means the format is text-based (and is to some degree human-readable). ASCII formats have the advantage of making it easier to spot problems with the file, and binary formats have the advantage of being smaller in size. DXF is an ASCII version of DWG, and is so easily understandable that it is possible to open the file and make edits to a 2D drawing with a text editor such as Notepad++ and repair or modify a file.

Most 3D models are far too complex to manually extracted, or manipulated so we can use metadata analytics to get information in the text format files. [in three-levels; Sub-objects(e.g., parts), Abstract-Level(e.g., surfaces), Basic-Geometries (e.g., lines)]

[The subject line of this post has been edited for clarity by cheryl.buck to include "- Informational"]