QCad User Reference Manual

# 3. Preface

## 3.1. CAD - For the Uninitiated

If you take a look around you, most man-made objects you see once started off as a drawing in a CAD program. Your ball pen, your desk, your furniture, your house and probably even your city - everything once had to be constructed either manually on paper or more likely with a CAD system.

CAD stands for Computer-Aided Design. It is essential to realize that CAD applications differ from simple painting or drawing programs. Drawings made in CAD applications represent real-world objects in their exact original measures. The most important aspects are accuracy and to provide a level of details that defines the object well enough that it can be manufactured based on the drawing. If you are used to simple drawing programs, you will most likely find it inconvenient that many steps are required to perform an operation such as moving part of the drawing. This is part of the idea, that everything is done accurately. The drawing does not only have to look accurate on the screen - it has to be accurate as a model of the real-world object. Moving an entity around means moving it from an exactly defined location to another exactly defined position.

Once you are used to this approach, you will most likle understand why this approach is superior to using other drawing applications for many tasks.

## 3.2. How can I get QCad?

You can get the latest version of QCad from RibbonSoft.com. On this web site you can also find more documentation, mailing lists and many other resources for QCad.

## 3.3. Is QCad for me?

There are many different CAD systems out there and depending on what you intend to do, QCad might or might not fit your needs. If you are looking for a 3D modeling CAD application, you will definitely have to look somewhere else. QCad is a 2D CAD program. That means that everything you draw is projected onto a plane. However, this does not imply that QCad is only suitable to represent 2D objects. A couple of 2D drawings which show an object from different perspectives (e.g. from the side, the top and from the front) provide usually enough information to fully define the object and all its dimensions.

Some of the main reasons why you might prefer QCad over other CAD applications are its simplicity, the user friendly interface, its features or the fact that it works on your favorite platform - be it Linux, an other Unix system, Windows or Mac OS X. Last but not least QCad is part of the open source movement. This means that its source code is available free of charge and if you are a programmer you can even add your own functionality.

QCad has an estimated user base of over 100'000 people worldwide. Its users range from industrial companies in the fields of mechanical and electronic engineering to private users, teachers and students. There are many other capable CAD systems out there and many of them offer more features than QCad. But most of them are bound to one single platform, hard to learn or are simply not affordable for many potential users. QCad targets the hobbyists, occasional CAD users and people who are not CAD professionals but still need to draw plans once in a while. QCad has been designed to be the CAD for the rest of us.

## 3.4. QCad and Qt

Qt is the cross platform C++ application framework that QCad is based on. Much of the portability and user friendlyness of QCad would not have been possible without the work of Trolltech ( trolltech.com), the company who develops Qt.

## 3.5. Scope of This Manual

This manual is designed to give an overview over the features of QCad. Its main objective is to be complete and cover all features and commands that QCad offers.

## 3.6. Who Is Behind QCad?

QCad is a product of RibbonSoft GmbH, a software engineering company based in Switzerland. Many people from the open source community have also contributed to QCad and it would not be what it is today without the help of many voluntary translators, developers and the feedback of QCad users. Please refer also to the company homepage of RibbonSoft for more information: RibbonSoft.com.