CADENCE AEC Tech News #107 (October 9, 2003)

8 Oct, 2003 By: Lachmi Khemlani

The Future of Autodesk Architectural Desktop

In the early days of the BIM phenomenon, Autodesk had one resounding message to send to its existing and future customers from the building industry-Revit was its BIM platform of the future (see Issue #90 discussing BIM and an Autodesk BIM event held in Jan 2003: We heard persuasive arguments as to why Autodesk had made this strategic decision, chief being that Revit was developed from the ground up with a single building data model and incorporated sophisticated parametric modeling capabilities and automatic change management capability. Revit had a fresh approach to BIM and incorporated the latest programming concepts, which meant no more "messy old code," as Carol Bartz, Chairman, President, and CEO of Autodesk put it.

This point of view was reiterated in the BIM debate between the representatives of Autodesk and Bentley in April 2003 (see Issues #95 and #96 at and, respectively). In contrast to Bentley's evolutionary approach, Autodesk continued to advocate the revolutionary approach to BIM with the new and powerful Revit application that specifically described a building from the ground up, rather than--as Phil Bernstein, VP, Building Solutions Division at Autodesk, stated-"build a solution by transferring existing AutoCAD-based geometry and drafting technologies that could not fully deliver on the potential of BIM.".

At that time, it seemed that the future of Autodesk Architectural Desktop (ADT), Autodesk's in-house building modeling application built on top of AutoCAD, was in question. Despite Autodesk's assurance that it would continue to develop and support both AutoCAD and ADT, how long would the company continue to put its resources into developing two competing applications for the same purpose?

In recent months, however, Autodesk has toned down its revolutionary Revit rhetoric and is positioning ADT as an equally viable BIM option. ADT is being pitched as an evolutionary solution for "building information modeling on the AutoCAD platform" with the best of both worlds-traditional drafting methods in an AutoCAD environment as well as efficiency gains through intelligent building model objects. ADT also got a shot in the arm with the release of the AutoCAD 2004 family of products, and the substantial improvements that were incorporated (see my review of AutoCAD 2004 in the June 2003 issue of CADENCE magazine: It now seems as though ADT will continue to be around at least as long as AutoCAD continues to survive and be in demand in professional practice.

Numerous Improvements in ADT 2004

Autodesk Architectural Desktop 2004 incorporates more than 300 enhancements addressing diverse aspects of the application such as ease of use, drafting and design, construction documentation, drawing and level management, design visualization, and file sharing and collaboration. Not only does it include all the improvements described in my review of AutoCAD 2004 (improved DWG format, redesigned interface with auto-hide and transparency features in modeless palettes, customizable tool palettes, improved multitext creation and editing, digital signatures, true color, gradient fills, and so on), it also includes several improvements specific to it as a building information modeling solution. These improvements address many of the drawbacks of the previous release (ADT 3.3) I had pointed out in Issue #73 comparing Revit with ADT (, written shortly after the Revit acquisition by Autodesk last year.

To start with, ADT now seems like an independent application in its own right, rather than an add-on to AutoCAD as it was in the past, when it simply added some additional menus and toolbars to the base AutoCAD application. The menu commands and toolbars in ADT 2004 are now much more integrated and don't have the AutoCAD-ADT differentiation. ADT also installs on its own without requiring AutoCAD to be installed, avoiding the inconvenience of competitor Bentley Architecture, which installs only if both MicroStation and Triforma are installed (see a recent overview of Bentley Architecture in Issue #104:

Creating and Editing Building Objects

The process of creating building objects has been simplified in ADT 2004, with less focus on dialog boxes and more emphasis on designing directly in the workspace environment. Take the simple example of drawing a wall. In previous versions of ADT, you had to select the Add Wall tool from the Walls toolbar. This opened up a separate, relatively large, dialog box-that sat annoyingly on top of the drawing window, taking up valuable screen space-where you could select the wall's style, height, justification, and offset value, and whether the wall segment should be straight or curved. In contrast, ADT 2004 lets you select a wall tool with a specific wall style from among several wall tools contained in a customizable tool palette, and just start drawing the wall. The default properties of the wall can still be seen and modified, if required, in the Properties palette, but you aren't forced to go through it as in previous releases. Moreover, with the new transparency and auto-hide features for the Tool Palettes and Properties palettes, no screen real estate is lost.

Editing objects is also a lot more straightforward in ADT 2004. There is no separate Modify dialog as in previous versions; instead, the same Properties palette can be used to specify the modification settings. Alternately, direct manipulation in the form of grips can be used to make quick design changes directly in the workspace, without using dialog boxes. For a wall, for instance, there are grips for stretching it, rotating it, repositioning it, or reversing its direction. Selecting a stretch grip conveniently displays the dimensions of the wall temporarily, making it easier to perform accurate modifications.

Some of the shortcomings I had pointed out in Issue #73 for element creation and modification, however, continue to exist. Taking the example of walls once again, there is still no shortcut in ADT for creating a set of walls enclosing a rectangular space, which is such a basic requirement. You have to draw four separate wall segments to accomplish that. You could draw a 2D rectangle and convert that to a rectangular set of walls with one of the options of the wall tools, which is very helpful when migrating 2D drawings to ADT. However, if ADT is being used to model a building from scratch, drawing 2D shapes and then converting them to building objects involve some additional steps and seems to run contrary to the concept of BIM.

Also, ADT is still woefully short of intelligent built-in relationships between building components. About the only predefined relationships that ADT has are those between door and window openings and the wall, slab, or roof objects in which they are inserted, so that if the parent object is moved, the inserted opening is moved with it. No other relationships between objects exist, either predefined or customized. So, if you move a wall, the other walls to which it is connected do not stretch to maintain the connection-you have to make such modifications yourself.

Thus, while element creation and modification in ADT 2004 have significantly improved from previous versions, it still has scope for improvement. In particular, building elements need to encapsulate more relationship information so that they can interact intelligently with related building elements, minimizing user intervention.

We will continue this exploration of Autodesk Architectural Desktop 2004 in the next issue.