Autodesk AutoCAD 2008 (Cadalyst Labs Review)31 Mar, 2007 By: Bill Fane
New annotations are the name of the game.
If you're looking for a buzzword that sums up the new capabilities found in Autodesk's AutoCAD 2008, your choices are annotations and interoperability with Inventor 2008. Okay, the second choice one is more than one word, but the Autodesk Inventor 2008 review will show you what I mean.
Back in the good old days when I started using Auto-CAD v2.18g in September 1986, drawing scales were a big problem. The manual was a detailed command reference, but it didn't contain any tutorials. Night-school classes and third-party documentation weren't available. In fact, that's why Cadalyst was started, and one of my earliest "Learning Curve" columns in January 1988 covered drawing scales.
There was no paper space and, hence, no layouts in the early releases. Users finally figured out that we should draw full size and then scale the annotation and dimension sizes to suit the plot scale. Multiscale detail views could be a real nightmare; heaven help anyone who tried to change the plot scale later.
Autodesk AutoCAD 2008
In theory, the current associative transspatial dimensions should take care of this adjustment, and for the most part they do. AutoCAD users draw in model space and then dimension and annotate in paper-space layouts. Even so, the debate rages as to where to place dimensions and annotations.
AutoCAD 2008 fixes all these problems with its new automatically scaled annotations. Figure 1 shows two red rectangles, which are two layout viewports. They show the same object at two different scales. As one would expect, the dimension text height and arrowhead sizes are the same and the dimensions show the same value. The surprising bit here is that the dimension and the word "SCALE" only exist once in model space. They have automatically scaled themselves to match each viewport scale.
Figure 1. AutoCAD 2008 annotations can resize automatically to suit the drawing scale.
You may think I'm cheating a bit here because the dimension and the word are in different locations in each viewport. Not so. They were created once in model space then two annotative scales were applied to each of them. Each scale setting can have a different associated position as well.
Point It out to Me . . .
A quick count of the new features suggests that approximately one-quarter of the new or improved capabilities in AutoCAD 2008 relate to annotation. Leaders alone have enough new features to be worthy of additional comment. For starters, users can decide to create leaders by selecting the start first, the end first or the annotation first (see figure 2). A single leader can have multiple leader arrows that lead to a single notation. Leader notation isn't limited to Mtext; instead it can use a block definition. This notation makes it possible to create symbolic leaders. A group of leaders can be edited quickly so that all their annotations align to a single horizontal or vertical line, and several block-defined leader annotations can be collected into a single leader.
Figure 2. AutoCAD 2008 adds new leader functionality.
You Break Me Up . . .
It isn't considered good drafting practice to have anything cross a dimension line, and similarly designers should avoid crossing extension lines. Unfortunately, these conditions can't always be met in a crowded drawing, so the new Dimbreak command allows users to break out a section of the line being crossed (figure 3). The beauty of this command is that the break specification can be automatic. The break will default to an order of precedence so that it will break extension lines before dimension lines.
Figure 3. The Dimbreak command will create associative breaks in dimension and extension lines.
As a bonus, the breaks are associative. If you move a crossing object, the break moves to follow. If you move the object to a position where it no longer crosses, the break heals itself. However, the break will reappear if you move the crossing object back into an overlapping condition.
A new inspection dimension allows users to include an annotation in a dimension that indicates the inspection rate as a percentage of total parts produced. By an amazing coincidence, Inventor 2008 also has added this same functionality.
If you need to list tabular data in an AutoCAD drawing, you'll love the new tables functionality. In previous releases you could create only a static, unpopulated table into which you entered data. AutoCAD 2008 can create a table automatically based on data contained in a Microsoft Excel spread-sheet or generic comma-delimited (CSV) file. Tables created this way can be static, or they can be set up as an external reference so that they update if the spreadsheet changes. Even better is the fact that they can be set up to work both ways, so that changes made within the AutoCAD table reflect back to the spreadsheet.
Layer upon Layer . . .
With AutoCAD 2007, the old Layer Express Tools no longer exist; they've all been rolled over into primary functions. In particular, I mean the layer manipulation tools. As an added bonus, additional layer functionality has been added.
A very useful new layer option allows users to assign different colors to layers in different viewports of the same layout. For example, one viewport can emphasize the wiring in a machine while another highlights the hydraulics in the same machine. Each viewport can still display the other objects for reference, but in a greatly subdued color. Both views are derived from the same model-space drawing.
Two layer-management tools will help to ensure compliance with CAD standards. Both are personal favorites.
I've always maintained that object properties should almost always be specified by the layer on which they reside. When Autodesk added the Properties Override toolbar, it claimed that users had total control over object properties. Wrong! Managers effectively lost any control.
In AutoCAD 2008, a new SetByLayer command asks users to select objects. When they do, all selected objects will have any property overrides stripped off so that everything is by layer. This command is so-o-o-o good that it even works down through block insertions, block definitions and nested blocks. Hallelujah! It also can be configured so that only selected properties such as color or line weight are removed. The second new layer functionality is just as good. The first time a drawing is saved, AutoCAD 2008 compiles a list of its defined layers. Whenever a new layer is detected during certain operations, an alert balloon pops up to warn users that the new layer isn't in the reconciled list. This functionality also applies to new layers created by Xrefs.
Workspaces were introduced a couple of releases back, and many people wondered why. AutoCAD 2007 gave us a hint to the reason with the introduction of the 3D dashboard.
AutoCAD 2008 now gives users a 2D drawing and annotation workspace, which includes a new 2D dashboard (figure 4). In effect, the dashboard is a super toolbar that includes the most commonly used 2D drawing, editing and annotating commands in one convenient location.
Figure 4. The new Drawing and Annotation dashboard groups put common 2D creation and editing tools together.
Before you comment about the amount of screen real estate that the dashboard occupies, don't forget that it effectively replaces nine toolbars. If you right-click within the dashboard and then select Control Panels, you can add or remove different groups of commands that roughly correspond with their matching toolbars. In addition, the dashboards can now be customized through the CUI (customize user interface).
Let There Be Light!
AutoCAD 2007 totally overhauled the 3D modeling and visualization (rendering) environments. Even so, lighting is an issue with nearly every rendering software. AutoCAD 2008 helps to resolve this problem by introducing photo-metric lights. Instead of placing a light and then playing with its color, intensity and so on, all you need to do is to go to the Photometric Lights tool palettes. From there, you can insert light sources such as 100W incandescent or 75W halogen.
Finally, the question of compatibility arises. AutoCAD 2007, 2004 and 2000 will open and edit an AutoCAD 2008 file in spite of new things such as linked tables and annotation-scale capabilities. They don't have full functionality in the older release, but they will survive a round trip back to AutoCAD 2008.
The perennial question from about 10 years back is "What can Autodesk possibly add to AutoCAD? It does pretty much everything a 2D-drafting package needs to do." Nonetheless, Autodesk always seems to come up withsomething. AutoCAD 2008 definitely continues that trend. Highly Recommended.
Bill Fane is a Cadalyst contributing editor and a professor at the British Columbia Institute of Technology. E-mail him at firstname.lastname@example.org