Moving from 2D to 3D for about the price of 2D: buy Autodesk Inventor Series, the solids modeler, and get Autodesk's 2D packages basically for free.

Autodesk, Inc. (San Rafael, CA) has a bundle for computer-aided design (CAD) professionals: the Autodesk Inventor Series, which includes AutoCAD 2004 (2D CAD), AutoCAD Mechanical Desktop 2004 (basically AutoCAD with a major mechanical bent), and Autodesk Inventor 7 (3D, adaptive solids modeler), with this bundle, users can migrate from 2D drafting to 3D solids modeling--easily and without losing 2D design data.

Such a hybrid design environment is possible through Inventor's 3D modeling kernel, the Autodesk ShapeManager. The kernel lets you work in both surface and solids design environments, and switch between the two on-the-fly, as well as mix surfaces and solids to create stylized and complex parts. This opens up traditional surface-only construction commands for 3D pros, such as loft with rails, replace surface, surface knitting, surface offset, and surface thickening.

In Inventor 7, ShapeManager also lets you create trimmed surfaces, and split surfaces with other surfaces, part faces, or sketch geometry.

The Inventor 7 user interface is also new. Similarities in design and operation to Microsoft XP are not coincidental. In addition, the solid modeler takes advantage of XP Professional's new ability to access up to 3 GB of system memory, which lets you work with larger assemblies. To better handle larger assemblies, Inventor can display only the relevant components. For example, you can place an engine onto the chassis and tell Inventor you're only interested in the engine block, versus the other internal information (such as connecting rods, lifters, and cams). Views can be quickly switched and turned on and off. This decreases the amount of memory required to assembly the models.

Inventor's user interface also includes "gesture-based interactivity." This is a neat feature where the CAD package responds to cursor movements, such as opening dialog boxes or completing design elements based on how you move the mouse. Moreover, Inventor's help system has become browser-based, something many consumer-based software packages provide. That said, there's still a 360-page "Getting Started" manual for us gearheads who like to nuzzle up to documentation not requiring electricity.

Inventor easily imports AutoCAD's DWG files and reproduces AutoCAD drawings, while maintaining the intelligence of the 2D design data. During import, you can preview the DWG file selected for translation, custom import and export of AutoCAD layers, and convert AutoCAD layers into title blocks, borders, symbols, or new 3D designs. You can also add "intelligence" to your DWG data, such as 2D parametrics, use existing 2D data in the context of a 3D assembly for conceptual design (adaptive layout), and use 2D data to create new 3D models. The same holds true for importing design files created in Autodesk Mechanical Desktop. Conversely, you can create AutoCAD DWG files in Inventor.

By the way, AutoCAD's new DWG file format creates files up to 50% smaller than previous DWG files. The revised format supports true color (16.1 million colors) and higher resolutions. However, while AutoCAD 2004 can save a file in a previous versions' format back to R2000, it cannot save a file to AutoCAD's R14 format, the last major release of AutoCAD before AutoCAD 2002.

Back to Inventor 7. It can import and export both STEP and ICES file formats, it supports Autodesk's own DWG and DXF, and it supports STL (stereolithography), SAT (ACIS), Autodesk VIZ, and, for output only, 3ds max.

There's one more file format that Inventor 7 supports: DWF (Design Web Format). DWF is akin to Adobe PDF in that users can distribute documents securely; DWF files are lightweight, non-editable, and well-suited for sending and viewing AutoCAD drawings over the Web. The latest version of DWF can be viewed and printed with Autodesk Express Viewer (included with Inventor or as a 2-MB download). This free viewer replaces the free Volo View Express, which could also view DWG, DXF, and Inventor formats (25-MB download). Besides being a new publishing format compatible with all Autodesk products, DWF capabilities include multiple 2D sheets, password support, and print-ready format.

Inventor 7's system requirements for "advanced" assembly modeling (more than 1,000 parts) are a Pentium IV, Xeon, or AMD Athlon 1.8-GHz processor or better, 600 MB hard drive space, 1 GB of "temp" space, more than 1 GB RAM and 2.S GB virtual memory space, and a 64-MB (or greater) OpenGL-capable graphics card. For smaller assemblies, you can get by with a 1-GHz processor and a 32-MB graphics card. Another requirement: Inventor only works on Windows XP (SP1 or later), 2000 Professional (SP2 or later), and NT 4.0 (SP6a or later).

The Autodesk Inventor Series is considered one package. Once installed, Autodesk Inventor 7 and Autodesk Mechanical Desktop 2004 can then be used concurrently or separately on that same machine. Network users can install both products, but they have a limit to the number of simultaneous users. However, new to this version, Autodesk lets you "borrow" Inventor licenses. FLEXlm 8.3 (those lower-case letters suggest "license management") lets you "check out" a network license lot a limited time, and then return that license to the server when you reconnect, time out, or release the license. You can temporarily work without a connection to the license server.

In the past, users often turned to "mid-market" CAD packages, versus say Unigraphics. I-DEAS, and CATIA, because they didn't have a lot of cash. Now they're turning to the mid-market packages like Inventor explicitly for the feature/functionality that those packages provide--feature/functionality typically found in the higher-priced competition, The Autodesk Inventor Series costs $5,195/ license. That price does not equal $4,195/ license for AutoCAD Mechanical 2004 plus $3,750/license for AutoCAD 2004. Something is coming free: The ability to move between 2D and 3D.