The history of CAD software can be traced back to the early 1960s, with the development of Ivan Sutherland’s Sketchpad at MIT. It was arguably the first commercial graphic computer software and it’s considered the origin of all CAD programs. Sketchpad brought the basic principles of technical drawing to a computer program and used what’s known today as a light pen as the input tool.

The first CAD applications were restricted to the automotive and aerospace industries, with big companies like Renault and Lockheed pioneering its use. While the 70s saw the arrival of 3D solid modeling, it was often used simply for producing 2D drawings that were merely a replacement of handmade designs. Later, CAD software started to reach a broader public since personal computers were becoming increasingly affordable.

By the following decade, some of the most popular CAD software we know and use today was developed. Dassault Systèmes released the surface modeler Catia, while the young Autodesk announced it’s most famous 2D software: AutoCAD. In 1987, Pro/Engineer (now Creo) changed the CAD market by introducing its solid modeling technique, shifting the design focus towards the 3D environment.

From that point on, it was pretty clear that CAD software was going to drive profound changes in the way designers, engineers, and architects would work in the future.

Benefits

There are several major perks to using CAD tools:

• Improves design quality: The huge flexibility provided by CAD enables better designs to be conceived. It’s much easier to understand, diagnose, and propose solutions using a variety of features that were made specifically towards these goals. This, as you can imagine, tends to result in better products overall.
• Increases productivity: It’s a fact that designing entirely by hand can take a huge amount of time. CAD software allows for a faster and smarter workflow, leading to quicker project conclusions. The fast-changing environment CAD provides was a true game-changer in terms of product development, reducing new products’ time-to-market immensely.
• Enables collaboration: CAD software provides the perfect platform for collaborative work. Complex products and assemblies usually require a huge team of designers and engineers, and effective communication between them is crucial. Cloud-based CAD applications are becoming the norm, which also contributes to enhanced productivity.
• Streamlines documentation: It goes without saying that record-keeping is a major issue when dealing with thousands of component designs. Imagine when that was all done on paper! CAD software has a central role in “product lifecycle management”, enabling automated systems to digitally store and safely keep entire design processes.

Drawbacks

While the many advantages of CAD surely outweigh any disadvantages, there are still a few major downsides, mostly related to cost.

Software licensing can be very expensive and the continuous enhancement of graphic tools requires more powerful workstations to use them. Also, top CAD software has quite a steep learning curve, usually requiring lots of time and money spent on training.

CAD is used by professionals in many sectors, but three of the biggest are engineering, architecture, and product design:

• Engineering is perhaps the area that has most benefited from CAD software. It’s used daily by all engineering fields, including mechanical, civil, and electrical. CAD is an essential tool for product or component development, used throughout the entire process, from concept to manufacturing and even after-sales support. Together with CAM software, which sends instructions to machines for manufacturing, this paired solution streamlines manufacturing in a way never seen before.
• Architecture is yet another area that CAD has hugely impacted. It’s mostly used by architects for 2D drawings, replacing paper with small digital files that can be shared instantly. In more recent years, 3D modeling has been increasingly applied in architecture for better spatial visualization, boosting client communication, and providing an excellent tool for interior design, as well.
• Product design applies the use of CAD for development and validation. While the development has had more or less the same gains as in engineering applications, a product concept’s validation is enhanced by CAD and other add-on tools, like rendering and simulation. A new product’s functionality and aesthetics can both be verified in a digital environment before allocating resources for early prototyping.

There are many different applications for CAD software, as we just saw. While most CAD solutions have industry-specific functionality, one could generally categorize them into two groups: 2D and 3D.

2D CAD

As implied, this CAD software works within the two-dimensional space, mainly replacing the tedious art of hand drafting. 2D software bases its designs on technical drawing principles, where three-dimensional objects are represented by graphical projections and information is conveyed through dimensions, text, standardized symbols, notation systems, and visual styles.

While it’s still used in many traditional industries (mechanical, electrical, aeronautical), it’s in architectural and civil engineering applications such as floor plans, landscaping layouts, building permits, and inspection plans that 2D CAD shows it’s strength.

3D CAD

Three-dimensional modeling is the natural evolution of flat, projection-based representations. The ever-increasing processing and graphic capabilities of personal computers have allowed these 3D tools to flourish and become very popular.

3D models can be visualized at any angle, and this more realistic representation provides a better understanding of design issues and enhances the whole communication process, in general. Eventually, some 3D designs can be converted to a 2D environment for manufacturing purposes.

Intricate parts and assemblies within the mechanical engineering world are far better represented by 3D software. Manufacturing industries like automotive benefit the most from 3D CAD.

Modeling Types

3D CAD software can be further categorized according to modeling technique, of which there are three main types:

• Wireframe modeling: It’s the simplest type that uses lines and curves to represent a 3D object. While it can be a quick way to demonstrate concepts through simple mock-ups, fully-detailed models can be extremely dull to make.
• Solid modeling: This is the most commonly used modeling type for engineering and 3D printing applications. Solid modeling is a step-up from wireframe since it incorporates additional physical properties like mass and volume to the model.
• Surface modeling: This type is a complex way to model objects and is best used for organic shapes. Freeform surface modeling represents a 3D object through skins and connected surfaces.

Computer-aided manufacturing, or CAM, it’s yet another computer software suite that had a profound impact on the manufacturing industry.

While CAD automates the design and technical documentation, CAM is used to automate the manufacturing processes, translating CAD designs into detailed instructions for manufacturing machines, in a way similar to what 3D slicers do with STL files.

It’s a common misconception, but CAM tools aren’t a substitute for CAD. While it’s true that some CAM applications include basic features related to design, it’s simply impractical to use it for proper design. That said, certain CAD programs include CAM capabilities, like Fusion 360’s different manufacturing modules.

The world of CAD is vast. There are various options for all different users, including professional, free, cloud-based, and browser-based. There are also many industry-specific solutions out there, with specialized modules, tools, and wizards.

With that said, there are certain names in the CAD world that have become major references in the market, offering a wide range of customizable software and modules that can handle any specific application.

Some of the most-recognized CAD programs used professionally are SolidWorks, Catia, Siemens NX, Autodesk Inventor, and AutoCAD, among many others.

For 3D printing enthusiasts, Fusion 360 is perhaps the most popular, being completely free of charge for students and small companies. For other free CAD alternatives, see this list with our best selections for 3D modeling.

We’ve seen in this article how CAD has for decades impacted many sectors by providing a digital platform for interactive design.

In recent years, CAD has also enabled a series of new computational solutions that have revolutionized the way many products are conceived. CAM, for example, has automated the complicated process of manufacturing those digital designs in a very fast and accurate manner.

CAD has also allowed a new generation of software to be developed: computer-aided engineering, or CAE. This software works together with CAD for in-depth structural, mechanical, or thermal analysis through computational simulation. In fact, many CAD has built-in CAE modules that enhance design since it allows an extensive design iteration based on simulation results.

Topology optimization, for example, is a tool born from CAE analysis and has been recently popularized together with 3D printing. This tool applies a mathematical algorithm that optimizes the material usage in a given part according to the real set of loads and stresses that it will experience.