Computer Aided Design

Computer-aided design (CAD) includes all of the geometric modeling software and techniques used to design, test virtually – using a computer and digital simulation techniques – and produce products. products and the tools to make them. CAD was first introduced in 1957 with the very first software, PRONTO, made for General Electric by Patrick Hanratty.


Ivan Sutherland's SKETCHPAD system, projecting a chair.


Realistic rendering of a dining room - @dezzavustudio

In these images we can perceive the complexity of the tools and the work done for the tools used today. With the new interfaces and calculation engines, the results are now much closer to reality in terms of drawing, movement and simulations.

With the democratization of digital and the availability of new software packages, the use of CAD is accessible to users with less scientific profiles and is becoming the basic tool for creating products.

Hobbyists, independent craftsmen, workshops, FAblabs, start-ups, design offices and technical offices of large companies now use CAD to materialize objects of all kinds.

CAO et DAO (dessin assisté par ordinateur), sont deux notions que l’on confond bien souvent. La CAO n’a pas pour fonction première l’édition du dessin. Il s’agit d’un outil informatique souvent lié à un métier, permettant l’organisation virtuelle de fonctions techniques. Cela permet ensuite la simulation de comportement de votre concept, l’édition éventuelle de plans étant automatique et accessoire. En DAO, un trait est un trait et le logiciel ne permet pas l’interprétation technique de l’ensemble.

wikipedia. CAO

How to use CAD

Using computer-aided design

The use of computer-aided design can be used in various fields with different approaches and software used. Before embarking on the creation of 3D files, it is important to know the type of files and plans you need, without forgetting the management of these. Between a 3D animated character and an object to be manufactured, the development approaches are very different. The characteristics of the 3D object, to be taken into account when choosing your software, must meet the expectations of your project. The use of different CAD software is relatively similar because it is done on the basis of common functions such as 2D sketch, extrusion, revolution, smoothing, rounding, etc.

Which 3D tool to use for the materialization of ideas ?

To date, there are about 50 software dedicated to the creation of 3D elements. A real jungle when it comes to choosing a solution to develop our projects. To enlighten you among the existing software in 2020, we have selected those dedicated to parametric design.

Among the various solutions available we encourages you to use solutions distributed under free license, according to the limits of the needs for your project.

Which files to use for exchanges?

Nowadays there is software that is said to be multi-environment, which allows you to directly open and modify native files from different developers. Native files allow you to dynamically modify all the functions of your 3D object. In the case of exchanges between software, there are various types of files containing several types of information related to the 3D object in question.

​STEP FILE (STandard for Exchange of Product model data with extension .stp)

​This 3D file format, managed as an ISO standard, takes into account references, surfaces, bodies, components, assemblies and sub-assemblies with textures and  ​others. This is the type of file used for CAD, CAD/CAM, Analysis, Data Management, etc. exchanges.

STL FILE (STereo-Lithography with .stl extension)

​The STL file format is a format used in stereolithography software and dedicated to rapid prototyping, which makes it possible to manufacture solid objects from a  ​digital model. The STL file represents the external surface of an object by coordinates of points in x,y,z.

​By analogy, the STL file is to 3D files what the TXT file is to text files.

OBJ FILE (Wavefront OBJ .obj)

​The OBJ format was developed by the animation industry and is used for sharing 3D objects on a large number of 3D software including some CAD software. In this  ​AsCII format, a polygonal surface is described by a set of vertices (with texture coordinates and normals at each vertex) and a set of faces.

In the field of 3D gaming and art, other types of files are used to transmit different metadata.

CAD Rules and tips

Mastering design rules requires time, case knowledge and above all practice. Below is a reminder of some important rules for a successful 3D design:

  1. Detail and dissociate as much as possible the different functions according to the geometric functioning of your objects.
  2. Name the functions created, clearly, in the model tree.
  3. Have a reasonable number of entities per sketch and ensure that all entities are constrained as needed for your object.
  4. Ensure the dynamism of your model by making maximum use of the references of the basic construction entities of the model (landmark, axes, planes).
  5. Give a construction order to your model, modeling the indirect functions last (roundings, chamfers, etc.)
  6. In the case of assemblies, define the number of components per file according to their interactions, in order to simplify the updates of volumes during the project.
  7. The repetitions of standard components followed by a rigid group saves considerable time in the design of assemblies.

CAD Models

Ecrin en bois

Création d’esquisses simples, désignation des corps et création des composants de la boite en apparance bois avec assemblage de charnières cylindriques connectées.

Visionner et télécharger gratuitement le modèle 3D  :


Création complète du modèle 3D d’un Stylo multi-couleurs avec création de répétition de composants, création de groupes rigides et définition des apparences.

Visioner et télécharger gratuitement le modèle 3D  :


Tabouret d’Atelier

Création des corps avec utilisation de taraudages et filets 3D avec liaisons des composants.

Visioner et télécharger gratuitement le modèle 3D  :

Parmi les différentes solutions disponibles vous encourage à utiliser des solutions distribués sous license libre, selon la limites des besoins pour votre projet.