By Jerry Laiserin
Savvy software buyers steer clear of "1.0" versions of any product, on the reasonable assumption that the developer's eagerness to ship something, anything, typically outweighs the prudence and polish that comes with mature products. Version 1.0 of Revit, a parametric modeling program for architecture released in April 2000, seemed to break that pattern. In its initial release Revit behaved like a child prodigy, talented far beyond its tender age. However, upon closer inspection and with a bit of hindsight, Revit 1.0 appears to have been more like an idiot savant-brilliantly capable of complex and arcane feats, yet quirkily incompetent in the mundane details of ordinary life. Fortunately for Revit Technology Corp. and for architects seeking intelligent, object-based CAD tools, Revit 3.0 has outgrown its childhood infirmities.
Revit's strength was and is the fact that it takes a "parametric change engine" approach to architectural design, in which all parts of a building model-even the dimensions and annotations that document and describe the model-are linked to and from all other parts of that building model. This two-way interconnectedness, also known as bi-directional associativity, enables designers to edit any entity in any view with confidence that the effects of their edits will ripple appropriately throughout the model. Coordination, or the tedious process of checking and ensuring that floor plans, elevation views, section cuts, and so forth are properly aligned within a set of drawings, becomes virtually automatic. The weakness of Revit's first release, however, was that there wasn't much to show in those nicely coordinated views.
In Revit 3.0, the ability to model and de tail real construction materials and assemblies has caught up with the program's ability to manage changes to the model. Walls, floors, and roofs in Revit 3.0 now can be composed of any number of layers and thicknesses of diverse material representations, directly corresponding to physical building construction.
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| Revit incorporates Robert McNeel & Associates' Accurender, which enables users to create photorealistic visualizations of building models. |
Also, Revit 3.0 is capable of much more complex building geometry than in previous releases. Detail drawings, which represent magnifications of critical connection or transition points in a building model, can be defined with view-specific linework to better match the drawing presentation conventions of traditional hand drawings and their drafting-oriented CAD replacements.
Early versions of Revit had limited support for multi-user projects because each user worked in a copy of the entire building model. Revit 3.0 introduces "worksets"-effectively subsets of the single overall building model that contain just the active work items assigned to or in use by an individual project participant. When multiple worksets are recombined and reconciled in the master building model, users gain the benefits of the overall parametric approach while still being free to work separately.
In earlier versions of Revit, users could work collaboratively with each other and exchange information with others via Au toCAD's DWG drawing file format. In version 3.0, users can also now import and export information in the DGN design file format of Bentley Systems' Microstation. Further, Revit 3.0 adds the ability to combine its CAD vector-based imagery with imported raster-based images in the same view or plot, and ex port combined raster/ vector drawings as JPG image files for presentations or Web publishing. Taken together, the added documentation and detailing functions in 3.0 put the product at least on a par with its immediate competition (programs such as Graphisoft's ArchiCAD).
Revit Technology's am bitions for its namesake software have always gone beyond just keeping up with the competition, however. Revit's subscription-based pricing and distribution model holds out the promise that subscribers will benefit from continuous program improvements without the periodic disruption and incremental cost normally associated with "point-release" upgrades.
For instance, Revit 2.0 added features such as massing study-model capability and building-scale detailing. Version 3.0 takes the already built-in raytrace rendering functions of Robert McNeel & Associates' Accu render and adds radiosity, for realistic rendering of diffuse surfaces and materials. Revit also now supports dynamic walkthroughs of building models-in quick-shaded views for speed, or in full radiosity for realism-and it includes Accurender's procedural plants, memory-saving algorithms that "grow" on-screen plants rather than saving large geometric models of plants.
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| Revit has added extensive detailing and annotation capabilities that can be linked to the underlying building model. (Image courtesy Revit Technology Corp.) |
In addition to the standard 16-million color Windows palette, Revit 3.0 incorporates the Pantone color selection and color matching system, which is compatible with color calibration hardware for accurate control over printed output. Revit 3.0 also can save output as Adobe PDF files, which are increasingly popular for plotting and Web publishing of large-format architectural and engineering drawings.
Along with many of its object-CAD competitors in architectural design, Revit 3.0 adds drag-and-drop functionality for retrieving and inserting pre-defined building object representations, such as doors, windows, plumbing fixtures, and the like, from locally saved component libraries or from Web repositories-even directly from building product manufacturer Web sites.
While Version 3.0 is certainly an improvement over previous iterations of the software, the maximum benefits of Revit's integrated building model won't accrue until the company adds discipline-specific tools to bring engineering consultants directly into the architectural design workflow. Separate modules or functions for structural engineers, MEP (mechanical, electrical, plumbing) consultants, and construction managers have been rumored for some time, and would be a welcome complement to Revit's architectural capabilities. Similarly, collaborative work in Revit would be enhanced if the current workset method of sharing a project could be ex tended beyond the local network to include direct collaboration/synchronization over the Internet.
Overall, however, Revit 3.0 continues to deliver on the company's promise of a rapid development and release cycle to ensure high value in exchange for the company's relatively pricey, but all-inclusive, subscription model. With three full "point-oh" releases within the first year, all streamed to users at no additional cost, the company sends a clear message that the erstwhile prodigy will continue to grow into robust adulthood.
Architect Jerry Laiserin, FAIA, provides strategic consulting services to architects and their technology providers. He can be reached at
jerry@laiserin.com.
Price: $199 per month
Minimum System Requirements: Windows 98/NT/2000; Pentium II; 128MB of RAM, 100MB of free disk space
Revit Technology Corp.www.revit.com