CAD programs are notorious for their cumbersome command-line typed commands and obtuse hierarchic text side-menus. Users must know how to initiate commands and then remember the correct sequence of cryptic options, much of which accounts for the steep learning curve starting out with and keeping up with CAD. Drawing many entities requires data entered as numeric values from the keyboard, you see any graphical information on the screen.

The advent of graphical user interfaces with the point, click & drag of intelligent graphical and geometric input have produced vastly improved CAD control systems. Yet long established CAD systems have been slow to take advantage of the advances in user interface technology, leaving most of the pioneering work to visionary developers with small market share.

Today the focus of ‘leading edge’ CAD technology has moved to the field of 3D modeling. This stream leaves the limitations even of the electronic drawing board far behind. But there remain many areas of design and technical drawing where 2D representation is entirely appropriate—for example:

• control systems
• electrical schematics
• facilities management
• fire protection and security systems
• HVAC
• instrumentation
• landscape planning
• networks and telecommunications
• piping
• process plant design
• space planning

In recent years some very innovative operational ideas have been applied to 2D CAD products, and the three packages compared here represent the latest concepts in 2D drawing. They are sold at about the same price level, which has become accepted by the market as the ‘appropriate’ price point for 2D CAD systems.

Visio made a major impact on the 2D drawing market when the software was introduced in the early 90s. It became the ‘industry standard’ for office diagramming work throughout the corporate world. This came about through a combination of several key features – ‘drag & drop’ pre-drawn symbols, automated symbol interconnection lines, and its ‘smart shapes’ technology, which enables intelligent automatic variation of the symbols to suit the context and the user’s dragging of their size or shape.

Let’s clear up a possible confusion right now. Visio Corporation’s software product is also named Visio, so when you read of Visio the software company and Visio the software program, you need to understand there are two different meanings of the same name.

Having been so near-universally adopted by business, it is not surprising that Visio has now been taken over by Microsoft and may well become a standard option in the Office suite of software. So where does that leave its rivals, in particular the other two subjects of this comparison?

Visio by Microsoft
All Visio software variants (Standard, Technical and Professional) are based on the same core drawing engine. This drawing engine has always been exceptionally good for the types of drawing work that office people want to do, but it lacked some key capabilities required for it to be a complete 2D CAD system that technical drawing professionals could use for all their needs. It was squarely aimed at diagramming, where scale and dimensioning are not an issue. Visio could be used for things like house plans at a pinch, but with difficulty. As the Visio range developed more general CAD facilities have been added, particularly to the Technical edition. Technical and Professional editions both offer different extra add-on functions and content for specialised uses. The current Visio 2000 Technical can serve quite well for any 2D CAD task.

A typical Visio screen. Easy to use in a short time. The distinctive bright green stencils are the key to ease and speed of use.

People like me, with a CAD and design office background, tend to concentrate on the ‘Technical’ edition of Visio, which is the most ‘general-CAD-like’ version. It incorporates additional technically-oriented add-ons such as:

• a wealth of pre-drawn technical content 
• DWG, DXF and DGN import/export
• process engineering features
• facilities management features
• architectural/building services features

The major product from the Visio's standpoint is Visio-Professional, which is designed for management and corporate computer network administrators. It has built-in automated features that greatly facilitate keeping track of complex network systems and administrative operations. The low-cost base version Visio-Standard also sells in huge numbers for business diagramming work in offices everywhere.

Actrix by Autodesk
It is impossible not to form the opinion that Actrix is something of a copy-cat product to Visio. But it is not a ‘clone’ product at all – it has its own ‘personality’ and its own features. Autodesk clearly recognized the enormous market that existed for the new type of software that Visio had devised, and saw how those methods could be used alongside more conventional CAD techniques. Here we see two very similar products produced by companies that dominate two different markets. Microsoft/Visio look at 2D drawing from the viewpoint of office work, while Autodesk of course see it more from the perspective of the drawing office, and it shows in the products.

A typical Actrix screen layout is more CAD-like in appearance and because of this probably easier to migrate to from something like AutoCAD.

Actrix is also marketed in different editions—Business and Technical. The Technical edition is not surprisingly equivalent to Visio’s Technical version, and clearly aimed at the 2D CAD market as well as the business diagramming market. The comparison with Visio is somewhat unbalanced as since Visio has recently released their greatly enhanced and now widely available 2000 version. The currently available version of Actrix Technical parallels Visio’s earlier version 5.0. Actrix Technical 2000 has recently been released and will be readily available by the time you read this. I expect this will significantly narrow the difference between Actrix Technical and Visio Technical.

Visio can import data from AutoCAD DWG files quite well. As might be expected, coming from the same home turf as AutoCAD, Actrix makes its interchange with DWG work as thorough as possible. It also provides for interchanging with Visio data files while preserving all symbol intelligence. As Autodesk’s professional design office support moves more and more into 3D based systems, including their new 3D-solids mechanical design system ‘Inventor’ which owes nothing to AutoCAD heritage, it is a strong possibility that Actrix might eventually become their main 2D system, perhaps even replacing AutoCAD LT.

SmartSketch by Intergraph
While the new upstart company Visio was creating their innovative system, one of the oldest players in the CAD field, Intergraph, were applying themselves to the new possibilities provided by Windows. The result was Imagineer Technical, a superbly quick and easy to use 2D CAD system. Joel Orr called it "the next generation of CAD" —an apt description. However, despite accolades like this, Imagineer never caught on the the extent it deserved. Intergraph seemed intent on keeping it something of a secret! With a name change to SmartSketch, some updating and re-jigging of the program and a re-launch, I hope it will now get the marketing it needs in order to reach the many people who will really benefit from this software.

SmartSketch is more like a traditional CAD program in appearance, but it has some interesting differences onscreen and particularly in operation as you will find when when you begin to work with it.

SmartSketch is not quite in the same mould as Visio and Actrix. As Imagineer it was clearly a top class general 2D drafting and design tool that could be also used for office diagramming much more easily than conventional CAD programs. As a corollary, Visio was designed as a super-easy business diagramming tool that might also be extended to 2D drafting tasks.

The core of SmartSketch is its ‘smart’ cursor and ‘smart’ object-snap methods. Instead of the diversions to set snap modes and the need to set up temporary guide-lines, the cursor continually shows fleeting geometrical relationships to nearby or distant objects and relevant snap possibilities as you drag a new line-end around seeking the correct end-point for it. A lot of this came from pioneering work done by Ashlar Vellum on the Macintosh, but Intergraph have developed the concept further and created a very easy to use system.

You can group lines to make objects and make them retain geometric relationships to others, and to pivot or slide and behave in a proper mechanical manner. This makes it easy to animate mechanisms and check for clearances. Although only in 2D, this is a very useful facility and a valuable extension to a designer’s thought process.

Intergraph have now added drag-&-drop symbols with programmed behavior in much the same way as the core features of Visio and Actrix. It also has the automated interconnection system of those products, whereby connection lines auto-adjust if you rearrange the associated symbols. So in this latest version, SmartSketch really merges full CAD functionality with the ‘smart symbol’ drag-&-drop idea.

Conclusion
Visio and Actrix can interchange data with AutoCAD DWG files, Actrix perhaps more completely. SmartSketch can also work with AutoCAD DWG data, but in an even more integrated manner. It can actually work on AutoCAD DWG data files without translating them. It can also do this with MicroStation DGN data files. It is possible to work on a drawing comprising data from AutoCAD and MicroStation as well as created within itself. SmartSketch deserves to be more widely known. SmartSketch also provides direct access to data created with other Intergraph CAD applications such as SmartPlant.

These three products provide truly useful, powerful and easy-to-use new technology applied to 2D drafting. 2D CAD will never be the same! After using these it seems a real ‘drag’ going back to old-fashioned CAD.