AutoCAD 2007

I have reviewed every release of AutoCAD starting from version 2002 (see my reviews of AutoCAD 2006 and AutoCAD 2005 in AECbytes; reviews of AutoCAD 2004 and AutoCAD 2002 published in Cadence magazine are no longer available online), and all of them invariably ended by bemoaning the abysmal quality of its 3D modeling tools. The following are two excerpts from my reviews of AutoCAD 2004 and AutoCAD 2006 respectively:

"The last time I reviewed AutoCAD 2002, I wrote that some aspects of AutoCAD needing improvement—such as 3D modeling, texture-mapping, and lighting—had been completely untouched. Unfortunately, that statement holds true for AutoCAD 2004 as well. About the only improvement AutoCAD has made along the 3D front is a new file format, ASM (Autodesk Shape Manager) that makes it faster to open and save drawing files comprised of 3D solids. AutoCAD still has one of the most non-intuitive interfaces I've seen for 3D. Rubber-banding is very poor, making it difficult to see what you are modeling until you finish the operation. Heights of 3D objects cannot be interactively indicated in the vertical direction; instead, they have to be typed in or graphically indicated by drawing a line on the base plane."(Review of AutoCAD 2004, published in the April 2003 issue of Cadence magazine.)

"The only aspect of AutoCAD that has been consistently untouched in several releases is its 3D modeling and rendering capabilities, which badly need improvement. I have kept pointing this out repeatedly in all my AutoCAD reviews, starting with version 2002. I hope Autodesk can either overhaul these capabilities soon, or else, eliminate them altogether. It would be doing a great service to its vast user base, most of whom don't use AutoCAD's 3D capabilities at all, by providing them with a leaner and less expensive top-of-the-line drafting application that makes no pretense at being something it is not."(Review of AutoCAD 2006 in AECbytes.)

It is terrific to at last be writing a review of AutoCAD without the customary complaint about its dismal 3D capabilities! After years of neglecting to overhaul them, the new release of AutoCAD finally gives 3D its due with a completely redesigned interface and new capabilities for conceptual and detailed 3D modeling. In fact, the primary focus of the new release is on 3D, so this review is, in essence, a review of AutoCAD 2007 as a 3D modeling and visualization application. Let's see how it measures up to the capabilities of other 3D modeling solutions, many of which gained in popularity and established themselves primarily because the industry-leading CAD solution, AutoCAD, did not provide adequate 3D support before.

New 3D Modeling Capabilities

When you launch AutoCAD 2007, it presents you with two different workspace options: 3D Modeling or AutoCAD Classic. If you are migrating settings from a previous version of AutoCAD, there is also a third option, AutoCAD Default, which borrows from your earlier settings. Whichever workspace you choose, you can always change it later from the Workspaces toolbar. You can also save and use your own customized workspaces. The AutoCAD Classic workspace option opens with the default drawing template file, and displays the classic default interface. For the purpose of this review, we will focus on the 3D Modeling workspace option, which opens with a 3D view using a 3D drawing template file and displays an interface designed for working in 3D (see Figure 1). It includes a new dashboard comprising several control panels containing tools organized by function such as 3D object creation, navigation, visual styles, lighting, materials, and rendering. As with other AutoCAD palettes, the dashboard can be docked on one side or it can be floating over the graphics window with features such as Auto-hide and Transparency. Clicking on a control panel in the dashboard expands it to display a slide-out panel that has additional controls, and also opens up an associate tool palette with more tools and options.

Let's start by looking at the 3D object creation tools. You can create a variety of 3D solid primitives such as box, cone, cylinder, sphere, pyramid, wedge, and so on, and the operation of these tools, unlike in previous versions of AutoCAD, is up-to-date with current modeling standards and includes the proper rubber-banding that is needed for interactive modeling. In addition, the dynamic input feature introduced in the previous version of AutoCAD (see my review of AutoCAD 2006), which displays all coordinate and dimension values as well as command prompts near the cursor and updates them dynamically as the cursor moves, makes it easy to create accurately dimensioned models. So, for instance, if you select the Box tool and move the cursor over the graphics window, you can use the dynamic input feature to specify the correct starting point, and likewise specify the exact second corner and height by reading the dynamic display or by specifying it numerically (see Figure 1).

Once you have created the object, modifying it is very easy using grips, which have always been one of AutoCAD's strongest features. This requires no special tools to be selected. You simply click on the object, and all its editable grips are displayed, allowing you to reshape it as required. Thus, for a box, grips are available to modify its sides, corners, upper and lower faces, and its position (see Figure 2-a). In addition, if you press the Ctrl key and click on an edge or face, you can modify that as a sub-object, radically transforming the original shape of the object (see Figure 2-b). You can also draw an edge or face on a 3D object and use the Imprint command to make it a part of a solid (see Figure 2-c), and subsequently modify the new edge or face to further reshape the object (see Figure 2-d). This provides more flexibility in creating desired 3D forms.

In addition to editing using grips, another powerful modeling and editing tool is Presspull. This allows you to select any existing face of a 3D object and pull it outside or inside to add to or subtract from the volume of the object respectively. You can use this for the existing faces of an object (see Figure 3-a), or by imprinting additional faces on an object (see Figure 3-b) and pulling those inside or outside (see Figure 3-c). You can also use the Presspull tool to quickly create 3D objects from 2D closed shapes. While this feature is extremely useful, that fact that it is identical to SketchUp's Push/Pull tool (which was part of the application from the start and hugely contributed to its ease of use and popularity) does make it now seem like a routine rather than a truly revolutionary feature. Although, to be fair to Autodesk, it did have a similar capability in its now defunct Autodesk Architectural Studio application (see the AECbytes article, "The Rise and Fall of Autodesk Architectural Studio").

Other modeling and editing tools include those that are, by now, standard capabilities in all 3D modeling applications: the Boolean operations of Union, Difference, and Intersection; and operations such as Extrude, Revolve, Sweep, and Loft that can be used to create regular and freeform solids and surfaces from existing lines and curves. In addition, there is a Polysolid tool which is used the same way as the 2D Polyline command but which creates a 3D solid with a specified height and thickness and can be used to quickly model walls; other 3D transformation options such as 3D Move, 3D Rotate, and 3D Align; a Section Plane tool which provides a 2D or 3D section of an object along a specified plane; a Slice tool which allows non-planar sections of objects; a Flatshot tool that creates a flattened view of all the 3D solids and regions in the current view; and various other tools.

Navigation and UCS Tools

The new modeling capabilities in AutoCAD 2007 have been accompanied by vastly improved viewing and navigation capabilities. A pull-down list in the Navigation control panel of the dashboard provides quick access to commonly used preset views such as Top, Right, Southwest Isometric, and so on, as well as custom views saved by the user. You can also easily switch between the Parallel and Perspective projection view modes. In the Parallel mode, switching views animates them as they change from one view to another, which is a cool feature. In addition to Zoom and Pan, there are three different kinds of Orbit commands, a Swivel tool, a Camera tool for creating cameras to view the model from specific angles, and Walk and Fly tools for navigating through the model. Any navigation route can be recorded and saved as an animation that can be replayed later.

AutoCAD 2007 also provides enhanced UCS (user coordinate system) tools so that the workplane can be located and oriented more easily for efficient 3D modeling. While the world coordinate system (WCS) is the default workplane that is active when you open a new 3D file (as shown in Figure 1), you can specify a new UCS to align with the face of any object that you want to model on by using the New UCS tool and selecting the desired orientation and location in a number of ways. Even more convenient is a new feature called "Dynamic UCS" that appears as a button on the status bar. When this is active, the application automatically determines the planar face of a 3D solid that the cursor is currently positioned on and aligns the XY plane with it, allowing you to create objects on that face without manually changing the UCS orientation (see Figure 4). All specified points and drawing tools, such as polar tracking and the grid, are relative to the temporary axes established by the dynamic UCS.

Improvements in Rendering and Visualization

AutoCAD 2007 features several new and enhanced visualization and presentation features to complement its revamped modeling capabilities. Topping this list is the introduction of "visual styles" for the display of entities in the graphics window, applied through the Visual Style control panel in the dashboard. There are some predefined visual styles such as Realistic, 3D Hidden, 3D Wireframe, and Conceptual that can be selected from the dashboard; some additional styles have been provided in the associated Visual Styles tool palette. One of them is shown in Figure 5 at the top. You can further customize an applied visual style by changing different variables such as edge color, edge overhang, edge jitter, width of silhouette edges, and the visibility and color of obscured and intersection edges. Two examples of such customized visual styles are shown in Figure 5 at the bottom. Custom visual styles can be saved for re-use in the same or other projects. Just like the Presspull tool, the visual styles feature would have been quite revolutionary had it not already been popularized by SketchUp, where edge extensions and jitters were a critical component of the interface right from the start.

AutoCAD 2007 also includes the full gamut of lighting, materials, and rendering capabilities to be able to create highly photorealistic rendered images, as shown in Figure 6. In previous versions of AutoCAD, it was difficult to accurately place a light in a model and understand how it would affect the scene before rendering it. Also, materials were difficult to create, apply, and render, and the rendering parameters were difficult to understand and adjust, making the visualization process difficult and time consuming. In AutoCAD 2007, a new interactive light tool has been introduced that allows you to quickly and accurately place distant, point, and spot lights in a model. The light position and direction can be quickly modified using grips, and the effect of the lights on shadows can be seen in real time without the need to render the image first. The "sun" can also be set to any desired geographical location in the world, making it possible to do accurate sun shading studies. The application comes with over 400 predefined materials, which can simply be dragged and dropped onto any desired surface in the model. Materials scale automatically based on the size of the model, and new materials can be created, if required, using a new materials editor. The rendering itself has been considerably improved with the incorporation of the mental ray® rendering engine, also used in high-end visualization applications such as 3ds Max. The rendering parameters can be easily accessed and controlled from the Render control panel of the dashboard.

Other New Features and Enhancements

While the focus of the new release of AutoCAD is undoubtedly on 3D, it does feature some enhancements on the drafting front as well. DWF files can now be referenced for use as an underlay and the External References palette has been expanded to provide a centralized location for managing all image, XREF, and DWF referencing. All the layer tools that were previously part of the Express tools, such as Layer isolate and Layer freeze, are now integrated into the main application. In addition to the ability to publish drawings and models into 2D and 3D DWF files respectively, AutoCAD now includes a new driver that allows drawings to be plotted to the Adobe PDF format. However, the ability to publish models in the 3D PDF format (see my recent review of Adobe Acrobat 3D) is not available. And finally, files can be saved down to older formats as far back as AutoCAD version 14 to facilitate data exchange with other project members. This is critical as the DWG file format has been changed in AutoCAD 2007, supposedly to accommodate the new 3D capabilities.

Strengths and Limitations

With this release, AutoCAD can no longer be berated for having poor 3D capabilities. Its new modeling and visualization capabilities are now at par with other established modeling and rendering applications and the developers have done a nice job of integrating all the new tools and capabilities into a single Dashboard interface. The new 3D capabilities also build up on powerful drawing and editing features that AutoCAD has perfected over the last two decades including grips, snaps, object snap tracking, inferencing, and dynamic input, which adds to their ease of use. For a seasoned AutoCAD user, learning to use the new 3D capabilities should be a breeze.

The new capabilities of the application are also amply supported by good documentation. There is a New Features Workshop that guides you through the new features and is customized based on the version of AutoCAD you are upgrading from. It contains a series of animated demos, tutorials, and feature overviews, which are very useful in learning the new features. The application also ships with a concise paper manual entitled "Building Your World: Conceptual Design and Visualization with AutoCAD" which is entirely focused on explaining the new 3D capabilities.

If AutoCAD is being used as the drafting application for a design project, using it also for the preliminary conceptual 3D modeling as opposed to other 3D tools has a definite advantage, as you can use its Section Plane and Flatshot tools to directly generate plans, sections, and elevations for documentation of the design (see Figure 7). The Section Plane tool is especially versatile as it yields 2D as well as 3D sections, allows straight as well as jogged planes, and can also create section cuts with hatch patterns and colors. From a workflow perspective, it is a definite advantage to be using the same application for both modeling and drafting.

In terms of limitations, the lack of adequate 3D modeling capabilities that was AutoCAD's biggest one to date has now been eliminated. I found little to carp about except for the PDF support, which does not match up to that provided by vendors such as Adobe and CAD-specific PDF vendors such as CADzation; these provide PDF files from AutoCAD that are much smaller in size than its built-in PDF output. Also, useful as the Section Plane is for deriving 2D and 3D section cuts, it would be a lot more helpful to have section cuts that were associated with the model, so that they could be updated automatically when the model was changed.

Analysis and Conclusions

The biggest question, really, with regard to AutoCAD's new capabilities is whether they are coming too late. The competitive landscape in 3D modeling has changed significantly in the last five years, and at least in the AEC industry, SketchUp has been firmly established as the conceptual modeling application of choice. Most of the "cool" features in AutoCAD's 3D repertoire are already part of SketchUp, as pointed out earlier, with the result that the thunder has already been stolen from AutoCAD's release. Granted that AutoCAD is a true solid modeling application, which gives it the ability to create precise, detailed, and accurate 3D geometry that a surface modeler like SketchUp lacks, still, SketchUp's unparalleled ease of use and low cost will ensure its continued popularity among AEC users. What makes the situation even more difficult for Autodesk is that SketchUp is now not just the product of a small startup company; it was recently acquired by Google (see this news article on the SketchUp website) who can become a formidable competitor if it decides to pursue the CAD market in a big way.

Ironically, also, AutoCAD's 3D capabilities are coming at a time when Autodesk itself is pushing the use of model-based or BIM applications such as Revit and ADT in the AEC industry. From a workflow perspective, would users start their conceptual modeling in AutoCAD, develop the design further in a BIM application, and then come back to AutoCAD to do the documentation? That seems unlikely. In a future BIM-based scenario, more and more users will do their documentation within the BIM application itself (if they need to produce documentation at all, which hopefully, at some point will become redundant), in which case, why would they want to use an expensive application like AutoCAD just for conceptual design alone when there are other, less expensive, applications available for that purpose?

What would really make AutoCAD have a competitive edge in the conceptual design space is if it could incorporate some of the neat technologies from the discontinued Autodesk Architectural Studio product, which digitally simulated a physical design desktop where you could sketch, draw in 2D, and model in 3D, in reference to site photographs, other images, CAD drawings, and any other content needed for interactive conceptual design. Content was created in translucent document windows that simulated trace paper, allowing you to place one document over another and sketch over it, as you would in real life. Capabilities like this could bring some of the "Wow!" factor back into AutoCAD, which was there in ample supply in Architectural Studio.

All said and done, though, the AutoCAD development team deserves to be complimented on doing a great job in overhauling its 3D capabilities, making them powerful yet relatively simple to use, and integrating them seamlessly with the rest of the application. For the existing AutoCAD installed base that hasn't moved to 3D yet, the available of good 3D modeling and visualization capabilities within their application of choice may provide the needed motivation to start 3D design exploration. AutoCAD may be late into the 3D game, but as the saying goes, better late than never.

About the Author

Lachmi Khemlani is founder and editor of AECbytes. She has a Ph.D. in Architecture from UC Berkeley, specializing in intelligent building modeling, and consults and writes on AEC technology. She can be reached at lachmi@aecbytes.com.