AutoCAD

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AutoCAD 2006 drawing.

AutoCAD is a suite of CAD software products for 2- and 3-dimensional design and drafting, developed and sold by Autodesk, Inc.. The original concept of AutoCAD in the 1980s was to promote customization and feature extensibility, and was what made it especially appealing to customers. Most contemporary CAD products at that time offered little if any customization capability and most were far more expensive.

Modern AutoCAD includes a full set of basic solid modeling and 3D tools, but lacks some of the more advanced capabilities of solid modeling applications. AutoCAD can co-exist with such products as a 2D drafting tool. AutoCAD is a vector graphics drawing program. It uses primitive entities — such as lines, polylines, circles, arcs, and text — as the foundation for more complex objects.

AutoCAD supports a number of application programming interfaces (APIs) for customization and automation. These include AutoLISP, Visual LISP, VBA, .NET and ObjectARX. ObjectARX is a C++ class library, which was also the base for products extending AutoCAD functionality to specific fields, to create products such as Autodesk Architectural Desktop, AutoCAD Electrical, or third-party AutoCAD-based applications.

AutoCAD's native file format, DWG, and to a lesser extent, its interchange file format, DXF, have become de facto standards for interchange of 2D CAD data. AutoCAD in later years has adopted another file format known as DWF. These files allow selected DWG drawings to be compiled to one file. This allows distribution of the drawings to those without AutoCAD or similar packages. It also protects the drawings from manipulation by others as the drawings are rasterized inside the DWF file. DWF files can be viewed with a free program from Autodesk called "DWF Viewer" - this program allows users to both view and print DWF files. Another advantage of DWF files is that a large number of drawings can be compiled to a single DWF and be of a very small to reasonble file size for electronic distribution. In 2006, Autodesk estimated the number of active DWG files to be in excess of one billion. In the past, Autodesk has estimated the total number of DWG files in existence to be more than three billion.

AutoCAD currently runs exclusively on Microsoft desktop operating systems. Versions for Unix and Macintosh were released in the 1980s and 1990s, but these were later dropped. AutoCAD can run on an emulator or compatibility layer like Virtual PC or Wine, keeping in mind the performance issues that can arise when working with 3-dimensional objects or large drawings. AutoCAD exists in 14 language localizations, including many European and Asian languages.

1 AutoCAD LT
2 AutoCAD Student Version
3 Vertical programs
4 Templates
5 Blocks
6 Version history
7 See also
8 External links

[edit] AutoCAD LT

AutoCAD LT is a "scaled down" version of AutoCAD originally designed for laptop computers, hence "LT, LapTop". It costs less (approx. $1200-$1800 USD versus around $4,000 USD for the full AutoCAD). It is also available for purchase at computer stores, unlike AutoCAD which has to be purchased from an official Autodesk dealer. It was developed so Autodesk could have an entry-level CAD package available to compete in that price class. Today AutoCAD LT is marketed as a CAD package for those who only need 2D functionality. Compared to the full edition of AutoCAD, AutoCAD LT lacks several features. Most notably, it has almost no 3D drawing capabilities (though it has a full suite of 3D viewing functions for looking at 3D drawings created in other CAD packages) and does not include any programming interfaces, such as support for most 3rd party programs and does not support LISP programs. A full listing of differences is on the Autodesk website. AutoCAD LT originated by taking the codebase of AutoCAD and commenting out substantial portions, which allowed AutoCAD and AutoCAD LT to be developed simultaneously.

[edit] AutoCAD Student Version

AutoCAD is also sold at a significant discount to qualifying students. The student versions are identical to the full version of AutoCAD with the one exception of a plot stamp / banner that appears on all four sides of any printed drawings. The student version is available in two flavors: the 1 year Student Version costs around $160 and expires one calendar year after installation. The Academic Career License costs around $400 and does not expire.

Autodesk Student products are not for commercial use. Products include on-screen and print education disclaimers & print banners. Any blocks or cut/paste from a Student Product will transfer the banners to the new drawing, regardless of the license of the creating version. Student Portfolios do not include a printed manual.

[edit] Vertical programs

Autodesk has also developed vertical programs, sometimes called Desktops, for discipline-specific enhancements. Architectural Desktop, for example, permits architectural designers to draw 3D objects such as walls, doors and windows, with more intelligent data associated with them, rather than simple objects such as lines and circles. The data can be programmed to represent specific architectural products sold in the construction industry, or extracted into a data file for pricing, materials estimation, and other values related to the objects represented. Additional tools allow designers to generate standard 2-D drawings, such as elevations and sections, from a 3-D architectural model. Similarly, Civil Design, Civil Design 3D, and Civil Design Professional allow data-specific objects to be used, allowing standard civil engineering calculations to be made and represented easily. AutoCAD Mechanical, AutoCAD Electrical and Autodesk Map 3D are other examples of industry-specific CAD applications built on the AutoCAD kernel.

[edit] Templates

Templates were introduced into AutoCAD R14. Templates allow users to start a drawing from an example, and reduce the chance of accidental over-write of the example drawing. Templates are typically used to set up drawing's sub-structure (layers, fonts, units of measure) and sometimes contain graphics such as title blocks. Template drawings are saved with .dwt extension.

[edit] Blocks

In AutoCAD, blocks are versatile objects that can be created on-the-fly and reused in the same drawing or in other drawings. The use of blocks when repetition occurs represents a savings in the data a drawing must contain. When a block is used, the definition of the entities that make up the block are stored once in the drawing. Subsequent insertions of the block only require a small amount of information (size, orientation, layer, etc.) to reproduce the block. An AutoCAD drawing file (*.dwg) can be inserted as a block into another AutoCAD drawing. Conversely, a block can be exported to its own drawing with the WBLOCK (write block) command. Additionally, text data (called "attributes") can be attached to blocks and extracted in reports. On the Web there are many sites that provide AutoCAD blocks, linetypes, hatch patterns, etc. In version 2006, AutoCAD adds dynamic blocks, which have capabilities similar to the symbols used in Microsoft Visio. A more powerful and flexible use of blocks (and DWG files) is to "reference" them within other drawings, maintaining a link back to the source data. This is known as an External Reference or XREF.