AutoCAD 2008

After devoting the whole of last year's AutoCAD release to a much-needed overhaul of its 3D modeling and visualization capabilities (see my review of AutoCAD 2007), AutoCAD returns to its 2D roots with a vengeance this year, with a whole slew of 2D drafting and productivity improvements, most of which were developed in response to customer wish lists and feedback. There is no change of file format in AutoCAD 2008, making it a non-disruptive release that will be easy to upgrade to for users who have been clamoring for these improvements. Let's take a detailed look to explore what they are and how they work.

Annotation Scaling and Multileader Objects

Formerly in AutoCAD, if the same annotation had to be displayed or plotted at a consistent size in differently scaled layout viewports, it had to be tediously re-created multiple times in different sizes and on separate layers. To overcome this limitation and make the annotation process more efficient, AutoCAD 2008 introduces the concept of annotation scaling, where objects commonly used to annotate drawings such as text, dimensions, hatches, blocks, and so on have a new Annotative property associated with them. You can turn on this Annotative property for a single object or by object style, and associate multiple scales with it. You can then set the annotation scale for the layout viewports to control the size of the annotative objects relative to the model geometry in the drawing. There is also an option to control the visibility of annotative objects based on whether their associated scales match with that of the viewport. Thus, you can choose to turn off the display of all those objects if the viewport is set to a scale that is not supported by them.

The implementation of annotative scaling is not very intuitive and does take some time to figure out. It can be best explained with an example. All the annotative text shown in Figure 1 has the Annotative property associated with it. The difference is that the multiline annotation shown in Figure 1-a has two object scales defined for it (1/4"=1' and 1/8"=1'), whereas the rest of the text has only one object scale (1/4"=1'), as shown in Figure 1-b. You can see from Figures 1-a and 1-b how the multiline annotation displays differently in model space based on whether the Annotation Scale is set to 1/4"=1' or to 1/8"=1'. The visibility option has been set to show annotative objects for the current scale only, which is why in Figure 1-a, set to 1/8"=1' scale, the remaining annotations cannot be seen. Moving on to look at a layout viewport, you can see that the display for the 1/8"=1' viewport scale also shows only the multiline annotation (Figure 1-c), whereas the display for the same viewport set to 1/4"=1' scale shows all the annotation objects (Figure 1-d), as the same visibility option was also applied to this layout. The key aspect to note, however, is the size of the multiline annotation, which is the same in both viewports, despite the fact that they are set to different scales. The height of the annotation in the layout views comes from its Paper Space Height property set as part of its style, which in this case was 0.0625. Thus, the same annotation will print at a consistent size even if it is appearing in different scales in different viewports, without requiring the user to create multiple instances of the same annotation for use in different sheets.

Another key feature related to annotation scaling is the ability to modify the individual scale representations of an annotative object, so that it is best positioned and configured for a specific scale. This modification can be done using grips, as shown in Figure 2, where the annotative object at the 1/8"=1' is being repositioned. While this editing is being done, the display of the object at all the additional scales that have been defined for it is also temporarily turned on, so that you can see how the display at the current scale relates to all the others. Thus, in Figure 2, you can see the display of the object at the 1/4"=1' scale as well. The example shown is the same as the one used in Figure 1, the only difference being that the background color was changed to white in order to see the displays more clearly. You can also set the width and height of the text for each display scale separately by using the Text Formatting rulers.

The annotation objects shown in Figures 1 and 2 belong to a new object type in AutoCAD 2008 called "multileader" that is designed to make it easier to work with multiple leaders. You can create multileader styles similar to those for dimensions, tables, and text using the Multileader Style Manager, where you can specify whether the type should be Mtext or a block such as a detail callout or another kind of tag, along with their corresponding options. You can also specify the settings for the leader format, arrowhead, break, and so on, and whether the leader is annotative is not. The multileaders shown in Figures 1, 2, and 3 were created using an Mtext annotative multileader style called "global," shown in the Multileader toolbar in Figure 3. It also shows the different tools for creating and manipulating multileader objects. You can create a multileader object head first, tail first, or content first. Once you have created a multileader object, you can create multiple leader lines associating the same note with different parts of the drawing, as shown in Figure 3. There is a tool for deleting leader lines when necessary. For those who like their notes to be nicely formatted, there is a handy Align Multileaders tool, which makes it easy to not just to align a set of selected multileaders but also to space them out evenly and make their leader lines parallel to each other. Figure 3-b shows the result of applying the aligning and spacing options of the Align Multileaders tool to format the multileaders shown in Figure 3-a. Rounding off the new Multileader toolset is another useful tool that lets you group several multileader objects that have block content and attach them to a single leader line.

Text and Dimension Improvements

Text formatting in AutoCAD 2008 has been enhanced to make multicolumn text a lot easier to create and modify. You can choose between static columns of a specified number, where all the columns have the same height (except for the last column, which may be shorter based on the amount of text), or dynamic columns, where you can change the number of columns interactively based on the column width you set. Dynamic columns can be set to Auto height, where all the columns (except possibly the last one) have the same height, or to Manual height, where you can adjust the height of each column separately with grips. This is useful when you want, for example, to wrap the text around a drawing in a certain way (see Figure 4). Regardless of the type of column formatting, text automatically flows between the columns as text gets added or deleted—the column heights no longer have to be manually and tediously adjusted as before. You can also insert a column break, when required, to force text to start flowing into the next column. Additional settings such as the size of the gutter—which is the space between columns—can be specified in the accompanying Column Settings dialog, where you can also specify exact values for the other column settings such as width and height.

Other text improvements include better control over paragraph formatting with new tab styles, paragraph alignment, and line spacing capabilities; better import of text created in other applications with the paragraph formatting retained; and a new spell-check engine that lets you search the entire drawing or only through specified areas of the drawing's text, with the added ability to zoom to and highlight misspelled words so that they can be clearly seen.

On the dimensions front, AutoCAD 2008 includes a new tool to evenly space out parallel dimensions for a neater appearance, similar to the spacing ability of multileaders shown earlier in Figure 3. The same tool can also be used to align dimension lines with each other by entering a spacing value of 0. You can add a jog line to a linear dimension to represent a measurement whose actual value is not the same length between the extension lines. The exact position of the jog can be specified using grips. Dimension or extension lines can now be broken where they intersect geometric objects or other dimensions. Other dimension-related enhancements include the ability to control the location of the text of angular dimensions outside the angle being measured; if the text is specified outside the angle, an extended dimension arc is created to place the dimension text. Arc extension lines are also available when specifying the text location of radius, diameter, and jogged radial dimensions.

Enhanced Tables

Tables have been substantially overhauled in AutoCAD 2008 with several additional formatting options and more powerful data extraction and external linking capabilities. Table styles have been enhanced to include more options for borders and margins within tables and table cells. You can quickly create new table styles from existing tables in a drawing. In addition to table styles, you can define individual cell styles that can be applied to specific cells of the table. Figure 5 shows an example of a table style applied to a schedule, and the subsequent application of a new cell style called Right-justified to the last column only—all the other data cells in the table follow the left-justification option set for the table data as a whole. New number and currency formatting within rows, columns, and individual cells is available.

A table with a large amount of data can now be broken using grips into primary and secondary table fragments, in which the data automatically flows from one fragment to the next, similar to the multi-column capability for text shown in Figure 4. By setting the Positions option to Manual for the table in the Properties palette, its individual table fragments can be placed anywhere within the drawing instead of being forced to stay together. Another useful new feature is AutoFill grips, which work similar to the Fill Series in Excel, and allows you to drag and automatically populate table cells with incremental data such as numbers, letters, dates, and so on.

Importing Excel data into AutoCAD tables is now no longer dependent upon the standard Microsoft OLE (Object Linking and Embedding) capability but is instead facilitated by a direct bidirectional data link. The Insert Table dialog allows you to create a new Excel data link, which can include an entire spreadsheet or a specific range of cells, and use that data to create a new table, as shown in Figure 6. The linked Excel file behaves as an external reference and can be managed through the Xref dialog. If the file is changed, the user is notified and given the option to update the linked data in the table. You can also change the data in the table in AutoCAD and upload those changes to the Excel file. This allows all linked information to easily be kept current and in synch, without the hassle of updating the tables or external spreadsheets independently. You can choose to retain the Excel formatting of the table, or apply any of the table styles created within AutoCAD to it. Figure 6 shows the data-linked table set to the same table style defined in Figure 5.

Another way to create tables in AutoCAD 2008 is through the new Data Extraction capability. A Data Extraction wizard allows you to extract property data from objects in drawings (including blocks and attributes) and drawing information, when can then be linked to information in a Microsoft Excel spreadsheet and output to a table or exported to an external file. Figure 7 shows this process being carried out for all the door objects in a drawing, resulting in the eventual creation of a table capturing the attributes of all the three different door types.

Other Notable Improvements

In AutoCAD 2008, objects can display differently in individual viewports in the layouts while retaining their original layer properties in model space. This has been made possible by the addition of four new options in the Layer Properties Manager dialog associated with a viewport, allowing users to specify color, line-weight, linetype, or plot style as an override for that viewport. The list of overrides for a particular viewport can be seen through the Viewport Overrides filter in the Layer Properties Manager dialog, which is automatically created when property overrides exist for the current viewport. Another layer-related enhancement is the ability to isolate one or more layers to make it easier to work on specific parts of a complex drawing. The objects in the other layers get dimmed but they can still be still be used for visual reference as well as for snapping. You can specify the level of dimming through a control on the Dashboard, as shown in Figure 8.

Despite the focus of this release being primarily on drafting improvements, AutoCAD 2008 does include some lighting and rendering enhancements for its 3D users, demonstrated in Figure 9. The lighting capabilities have been improved to include a choice of photometric light sources, which use real-world values and allow for more realistically rendered images. It is possible to import the lighting data from IES files and apply it to any light object that has been modeled. For more realistic outdoor lighting, a new Sun and Sky background is provided with settings for capturing the intensity and color of sunlight and the atmosphere in a scene. Material rendering has been improved with the addition of new procedural maps, which are generated by mathematical algorithms and allow more realistic materials to be created as compared to texture maps. You can also apply advanced lighting overrides at the material level to adjust aspects of the light emission, reflectance, and color bleeding; this provides more rendering control than relying strictly on the light sources illuminating a scene.

Other enhancements include the ability to manipulate the visibility of layers in DWF files that are being used as underlays, import MicroStation DGN files as well as use them as underlays, and export AutoCAD files to the V8 DGN format. An Autodesk Impression toolbar provides access to Impression commands for those who have the application installed, and facilitates a smoother workflow between the two applications. The Layer States Manager dialog features improvements for editing and viewing layer states in attached Xrefs. A new Xref Clip option allows the hidden area to be quickly inverted, either inside or outside the clipping boundary. A new InfoCenter option on the menu bar allows you to enter keywords or a question for help, display the Communication Center panel for product updates and announcements, or display the Favorites panel to access saved topics. The layout tabs have been redesigned to work more intuitively, similar to sheet tabs in Excel. Several enhancements have been made for customizing the user interface, including adding, repositioning, and removing commands, creating new toolbars, and adding to or modifying panels in the Dashboard. AutoCAD 2008 runs on Microsoft's new operating system, Vista, and is also available in a native 64-bit version, which will be useful for those working with very large files.

A quick note about AutoCAD LT 2008—it includes most of the new features of AutoCAD 2008, except for data extraction and the lighting and rendering improvements.

Analysis and Conclusions

AutoCAD 2008 features a host of drafting productivity improvements, all of which should be very useful for the vast majority of its users who still rely heavily on creating drawings for their professional AEC work. Following on the heels of the last release which dramatically overhauled the 3D capabilities of the application, this release is a lot more modest in scope and ambition, targeted towards making day-to-day drafting tasks such as annotation, dimensioning, and creating and managing tables easier and more efficient. The focus is also on avoiding the duplication of data and reduced updating of data, with features such as annotative scaling and data extraction. For those who formerly spent a lot of time cleaning up their drawings to make them look neater, features such as spacing and aligning multileaders and dimensions will prove to be a real time-saver. Users who have taken advantage of AutoCAD's revamped 3D capabilities introduced in the last version will be pleased with the new lighting and rendering improvements, which go a long way towards producing superior quality renderings in a reasonable amount of time, such as the one shown in Figure 9 which took only about 5 minutes to generate.

One aspect of AutoCAD that I have repeatedly complimented in past reviews is the excellent quality of its documentation. There is a New Features Workshop, which contains a series of animated demos and feature overviews that are very useful in getting acquainted with the new features of the application. Also invaluable is a paper manual included with the installation CD that provides detailed tutorials on using the new features with the help of sample AutoCAD files, which are included with the program. The regular Help system accompanying the application is comprehensive and includes several video tutorials to illustrate specific features. In addition, the new InfoCenter field on the menu bar makes it easy to quickly find the appropriate section in the Help window for assistance with a specific feature. All in all, it is very commendable to see this much effort put into maintaining as well as enhancing the quality of the documentation, particularly in comparison with many other applications that fail to provide adequate learning support for their users.

Those in the AEC industry who have begun the transition to BIM may find it difficult to get excited about this release of AutoCAD, but considering that the big transition point from CAD to BIM is still estimated to be five to seven years away, any improvements in AutoCAD that can save time and reduce tedium for its users will be appreciated. From that perspective, AutoCAD 2008 can certainly be rated as a very useful release, and my guess is that Autodesk will continue to engineer several such incremental improvements in future releases. Of course, there are much less expensive drafting applications out there which can get the job done. But given that the writing is on the wall for CAD in general, AutoCAD users are likely to stick with AutoCAD and benefit from its improvements rather than bother switching to another application, especially when they know that they will have to eventually move to a BIM application anyway. Thus, AutoCAD has several more releases in which to perfect drafting to death, figuratively as well as literally.

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.