Zeroing In on Autodesk's Latest Release
by Peter Sheerin, CADENCE, December 1994.
Finally, Release 13 is making it out Autodesk's front door. For this review, we've taken some of the major features and put a magnifying glass on them. We have not gone into great detail on the Windows version because, at press time, it was not ready for review. The Windows version will have all of the features of Release 13 for DOS, plus a few others, including OLE support, enhanced menus, and a brand-new interface. Plenty of other new enhancements may not require a whole section to describe but are certainly worthy of mention.
One of the biggest changes in the DOS release is the inclusion of a display-list driver in the box, just as has been the case with Release 12 for Windows all along. The driver, licensed from Vibrant Graphics, is basically the same as its low-end driver, with the inclusion of an aerial-view (or bird's eye). Aside from the enhanced speed and interface this setup provides, the driver adds a feature certain to be cherished by all the single-screen AutoCAD users: a graphics-based text window. No longer does doing a flip screen (either manually or as a result of the LIST command, for example) switch to the standard black text screen, forcing the monitor to delay switch modes. Instead, the text output is mapped to the graphics screen, eliminating yet one more annoyance left over from the old AutoCAD.
The dialog-based help system that was introduced in Release 12 has been revamped and now functions very much like the Windows help system. Hypertext links and pop-up definition boxes are supported, along with a searchable index and navigation keys. Of particular interest, the new help system has two features that will be of use to all AutoCAD users. A comprehensive list and description of what commands have been added, changed, or removed between Release 12 and Release 13 will help make the transition easier for users. The reference manual is split into two parts, the User's Guide and the Command Reference. Autodesk has included the full text of the Command Reference in the help system, complete with hypertext links where appropriate. There are no graphics, but this setup will reduce the need to refer back to the paper manuals to learn about the less often used commands.
Another new item on the drive front is an enhanced HP-GL/2 plotter driver from Hewlett-Packard that provides many more configuration options. This driver is basically the same one that HP includes with its plotters, and it provides more control over HP-GL/2 features, such as line capping and line joining (beveled ends versus rounded, and so on), screened lines, raster pattern fills, and an option to combine one rendering onto an other wise normal vector plot. Also, due to popular demand, the included drivers finally support the HP DeskJet printers! Support is specifically included for the 500, 500C, and 550C in monochrome and color modes. The PostScript driver now supports 6OOdpi and adds the option to have either a <Ctrl-Z>, <Ctrl-D> character, or both to the end of the output.
Among many of the small changes to AutoCAD that begin the elimination of confusing behavior is a new method of entity picking. If you have selected one entity that is coincident with one or more other entities, it has not always been possible to select the one you were actually after or even see that there was more than one entity there in the first place. Now, at the time you select an entity, you can hold down the control key while pressing he pick button to cycle through all the entities within the aperture that you selected. Another fix along these lines is the ability to purge the drawing of unused blocks, text styles, and line types at any time - not just when the drawing is first opened.
While Release 13 has many features and enhancements, some capabilities have disappeared. Freeplotting (the ability to launch AutoCAD and plot without using up a network license), which first appeared in Release 12, has now disappeared, without the functionality appearing elsewhere. The one solution to this problem in the past was a "show demo" version of AutoCAD, which could plot and edit but not save drawings. It was an inexpensive product, but there is no guarantee that it will reappear. The built-in IGES translator has also disappeared. Even though it supported a very old version of the standard, but to get that functionality, you have to purchase Autodesk's separate, $1,200 IGES translator.
Despite all the information we've given you, there is a lot more detail to go into later. Keep your eye on our regular columns for more information about the inner workings of Release 13.
by Peter Sheerin
A Big shortcomming of AutoCAD has been its lackluster support for text - even though text is an important part, and sometimes large percentage, of your drawings. Previously, catch line of text had to be a separate entity. No word wrapping was performed, and although paragraphs could be formed, they were not a picnic to edit if the length of a line within a note changed. Release 13 adds of number of important enhancements that improve text handling, but it is still lacking a few features that would make it even easier.
A new entity, MTEXT, provides paragraphs text. Now, one text entity can span multiple lines and can be automatically word-wrapped at a given location. In addition to standing on its own, an MTEXT entity is used with the new associative dimension leader, so leaders can now have multiline text.
The addition of a multiline text entity requires a new method of input, beyond the simple command line. Here lies one of the limitations. While the Windows version of Release 13 will include a text editor specifically designed for the MTEXT entity, the DOS version doesn't include such an editor and, instead, relies on the user to have a DOS text editor, shelling out from AutoCAD each time and MTEXT entity is created or modified. This process is cumbersome because that text editor may or may not have a word-wrap function, and certainly won't know what the specified margins for a specific MTEXT entity were, even if it did. While the Windows MTEXT editor provides buttons and check-boxes to modify, properties of individual words and characters (just like a word processor), in the DOS version of AutoCAD, these setting must be manually specified by embedding special formatting codes in the text. Not providing an MTEXT editor in the DOS version was a mistake and is one Autodesk should fix quickly.
Also, while AutoCAD now supports TrueType and Type 1 scaleable fonts, its primary font architecture is still the old vector based SHX font. This setup means that while TrueType and fonts can theoretically have attributes, such as bolding and italics applied to them, SHX fonts have no such capability and Autodesk decided to make MTEXT editing less confusing by not implementing those font attributes. You can, however, specify one or more different fonts within each MTEXT entity. Because Type 1 fonts treat different styles as individual font files, you can achieve the desired appearance with italic, bold, and bold-italic versions of a given Type 1 font.
The allowed formatting includes stacked-fractions, overline, underline, nonbreaking spaces, color, tracking, width, and obliquing (an imitation of italics, but an incorrect one). Bold and italics are available in a font change. It is also possible to define a font-mapping file that provides two benefits. If you are sending a drawing to another AutoCAD user who doesn't have the same fonts as you, you can remap the fonts to different, standard AutoCAD fonts. You may want to use this feature for editing with standard AutoCAD SHX fonts (fast!) but switch fonts to filled Type 1 or TrueType (slow, but pretty) fonts easily and painlessly when it's time to plot.
While this may not be of interest to most of our readers, international AutoCAD users will appreciate the ability to redefine which direction the text flows. For those languages of the world that read from right to left, AutoCAD can now create text in that direction. It also can handle all the complex and numerous characters in foreign languages with its added support for Unicode fonts.
And last, but certainly not least (it has consistently been at the top of AutoCAD wish lists), DOS and Windows versions of Release 13 include a spell-checker. This spell checker is full-featured - similar to the one found in word processors, such as Microsoft Word - and even includes user-defined dictionaries (but no, not quite compatible with Word's dictionaries).
Peter Sheerin is the technical editor of CADENCE.
Recuadro: What's Hot? What's Not?
by John Gibb
It was with much anticipation that I dived into the new dimension features in Release 13. I had heard that Autodesk took the wish list seriously, and it had reworked dimensioning extensively. I was not disappointed. Well, not much. As you can see from my What's Hot? list, I do have one wish that was unfulfilled by this new version.
Not Associative to the Geometry
AutoCAD has had associative dimensions since early on in the development of the software. Unfortunately, the dimensions are associative only in the sense that they are aware of their own definition entities and definition points (control points). They have never been truly associative to the geometry that they annotate. That is still the case, and it is unfortunate that true associative dimensions have not been added. This complaint is small compared to the many new features and new user interface.
New Dialog Boxes
The DDIM dialog box and its child dialog boxes have been totally reworked. They are more intuitive for the various dimension styles you create and for the new process of creating dimension families.
The same dialog boxes you use to create a dimension style are used for creating the family members of a dimension style. You can simply pick the family type from the list of radio buttons and then Geometry..., Format..., or Annotation... button to setup the dimension variable for that family member.
While the child dialog boxes have been rearranged, their function has not been changed. The new feature in the boxes is the inclusion of image tiles that reflect the changes you make. You can pick on the image tile and you will toggle through the possibilities. Or, you might choose to use the radio buttons or pop-up list to make your choice.
Dimension families
This new concept makes it easier to create one dimension style that can look like multiple dimension styles. Now each dimstyle can have a separate setup for dimension types like linear, radial, angular, diameter, ordinate, or leaders. If you have a separate setup for linear dimensions in your style, AutoCAD will automatically use the changes when you place a linear dimension with that style.
Dimension Variable Overrides
Overrides are applied to individual dimensions in a dimstyle, and the dimension will still reference the dimstyle it was created with. No more UNNAMED dimstyle when you override a dimension.
Independent Dimension Units
Each dimstyle can now have its own units attached to it, independent of the drawing units. You can also use the override feature to assign different units to individual dimensions while the dimension keeps its dimstyle.
Extensive Arrowhead Support
You can now have no arrowheads, open or closed, arrowheads, right-angle, closed-filled, oblique, dot, origin indication, and user-defined arrow heads. More basic choices means less hassle.
Nonlinear Leader Lines
You can now have curved leader lines using the format option for leaders.
Geometric Dimensioning and Tolerancing
Mechanical Engineers and Drafters will be happy with the new tolerance command. AutoCAD now has Geometric dimensioning and tolerancing (GD&T) built into it. GD&T is an international standard used by the mechanical disciplines to define geometric constraints on any given desing.
John Gibb is an AutoCAD instructor and CAD consultant based in Chicago, Ill.
Recuadro: What's Hot? What's Not?
by Craig Sharp
While the 3D modeling capabilities of Release 13 DOS will be a welcome addition for people who find themselves building models of their ideas, the ability to visualize those results in impressive fashion is still left up to products such as AutoVision, 3D Studio, and other third-party renderers. The improvements made to AVE Render, important as they are, cannot be termed exciting. The speed of rendering in Release 13 is most definitely improved and is likely attributable to Rx ADS. Phong shading has been added as well as spot lights and the interface via dialog boxes is better thought out and more accessible. Most improved is AutoCAD's ability to exchange files with other Autodesk rendering products, which at least improves your ability to create impressive renderings from external applications. The relationship between AutoCAD and 3D Studio, AutoVision, and Visual Link has been unified, and true material libraries in MLI format are now supported in import and export fashion.
Even though not all of the effects of materials applications can be viewed in AutoCAD, they will, at least, transport back and forth between AutoCAD and 3D Studio or AutoVision using two new commands, 3DSin and 3DSout. Materials created in 3D Studio that have maps applied are imported by converting the map to a Targa file except for materials created using animation files that use only the first frame of the animation or IPAS routines. Furthermore, lights, meshes, materials, and cameras can be retained, and a variety of color, material, and object creation options are available. You can also select which objects will be imported into AutoCAD. AutoCAD will import a 3D Studio file and create layers based on how the model was created in 3D Studio, naming the lawers by the object's color, material, or object name. You can also import everything to one AutoCAD layer if you so desire. 3D Studio cameras are retained as views in AutoCAD, and objects are assigned a color approximating their 3D Studio color from AutoCAD's color palette. Ambient light loses any color assigned in 3D Studio, omni lights become point lights, and spotlights become spotlights. Finally, AutoCAD provides you with the option of splitting 3DS objects that have more than one material assigned to them. Exporting AutoCAD geometry to a 3DS file provides many of the same features as importing the 3DS file: adding the ability to split blocks or retain them as a 3DS object, creation of 3DS smoothing groups, and automatic welding of vertices.
The addition of Phong shading provides a more pleasing look to the treatment of materials and color in AVE Render and is necessary when using spotlights. Figure 1 shows a rendering that includes standard point lights, materials with a variety of ambient, specular, and roughness settings, and the addition of the new spotlights. Unfortunately, setting the hot spot and falloff of the spotlight cone is not a dynamic process (you can't visually adjust the size of the cone) and requires some rather arcane guesswork to obtain the proper settings. Even more disappointing is the fact that no form of shadow casting is included with the spotlights.
Therefore, the final effect of the placement of the spotlights for use in a more sophisticated rendering environment cannot be visualized.
The Render menu is now placed under a Tools pull-down menu, which is more appropriate for the frequency of use of AVE Render. Once you trickle down to the desired render command, dialog boxes are presented that place the rendering options more readily at hand and in a less obscure fashion than those of Release 12. The naming, selection, and application of materials from two dialog boxes using a materials library is certainly a welcome improvement and you can now assign materials by layer in addition to Release 12's way of doing it by color and entity. Finally, you can render directly to a file instead of first rendering to the display and then saving the image to a file. If you own a third-party rendering program, you will appreciate the additions to AVE Render for Release 13. If you want AutoCAD to do your renderings for you, you will be pleased with the increased speed, improved interface, and improved display of color via Phong shading but you will find yourself still waiting for a real rendering environment.
Craig Sharp is an architect with Motley and Associates in Roanoke, Va. He is the author or coauthor offive books on Autodesk products and has been using AutoCAD for eight years.
Recuadro: What's Hot? What's Not?
by Ralph Grabowski
With ten programming interfaces, it would seem that AutoCAD is a rich enough environment for developers. In Release 13, Autodesk has created yet another applications programming interface (API) it calls Rx. This API promises an even tighter integration of third-party programs with AutoCAD.
Rx applications are like dynamic link libraries (DLL) under Windows. A DLL is only loaded when the application requires it. Then, the DLL loads automatically. Rx applications retain their DLL status even when running under DOS. Smaller AutoCAD developers are not happy that employing Rx required a 32MB computer running Windows NT - even for DOS-based Rx applications. At the time of this writing, Autodesk was still creating the new API and did not expect to finalize it or the documentation until after Release 13 ships.
The other significant change to programming Release 13 is the ability to load menu fragments. Currently, to change a menu, an entire MNU file must be loaded. Release 13 is able to load portions of an MNU file, as required.
Command Compatibility
As you would expect, Release 13 has many new commands. What developers might not expect is that a number of existing commands have different names. This news is bad and good - bad because AutoCAD veterans have to retrain their fingers, in some cases, and good because Autodesk has integrated the appendix commands, such as Dim:Hor and (xload "ASE") AseEraseTable, to make them more like core-code commands.
If you customize AutoCAD in any way, you need to be aware of the blatant and subtle changes to the command set. At the time of this writing, the beta version of Release 13 contains more than 70 new and changed commands. The 33 new commands in Release 13 are:
3DSin, 3DSout, Acisln, AcisOut, AmeConvert, BmpOut, CloseDwg, CopyHist, DdColor, DdGrouP, DdLtype, DdStyle, DdToolbars, Group, HatchEdit, InsertObj, Lengthen, MenuLoad, MenuUnload, MlEdit, MLine, MIStyle, MText, OleLinks, PasteSpec, Ray, Rx, SaveAsRl2, Spell, SplinEdit, SysWindows,VIConv, XLine, and Xplode.
As is common in AutoCAD, many commands have additional options. Some commands, such as InsertObj and OleLinks, are specific to the Windows version of Release 13. Many of the commands with changed names are external routines that Autodesk rewrote as Rx programs. In some cases, Autodesk reduced the number of commands required to use a feature. The most dramatic example is in ASE, where just six commands replace 31. The dimension, AVE, ASE, and AME commands have been renamed, as follows:
File Compatibility
For the first 10 releases of AutoCAD, Autodesk made the DWG file format incompatible with previous versions. In Release 11, John Walker wrote Dxflx to convert Rll drawings to RIO via DXF. In Release 12, the DWG format was not changed, allowing Release 11 to read R12 drawings.
With Release 13, the DWG file format has dramatically changed again. However, for the first time, Autodesk includes a native backward translator, the SaveAsR12 command. The command saves the current drawing in Releas 12 format, converting or stripping out incompatible Release 13 entities.
The internal IGES translator has been dropped from Release 13. Because Autodesk had never bothered to upgrade the translator from its rather ancient version 3.4 standard, this change isn't a big deal; however, Autodesk's up-to-date version 5.2 IGES translator is an additional $1,200.
The AME in Release 13 uses ACIS-based modeling, unlike the PADL-based modeling used in the AME of Release 11 and 12. The new AMEconvert command brings solid models created in earlier versions of AME into Release 13. To read solid models created by other ACIS-based modelers, Release 13 includes the new ACISin and ACISout commands.
To tie AutoCAD more closely to 3D Studio, Autodesk had released Visual Link. In Release 13, the optional software package is no longer needed. The new 3DSin and 3DSout commands read and write 3D Studio files; the new VlConv command converts files created by Visual Link.
Ralph Grabowski is the author of 14 books about CAD. His newest books include The Illustrted AutoCAD Release 13 Quick Reference for DOS and Windows from Delmar Publishers. He is based in Abbotsford, B. C.
Recuadro: What's Hot? What's Not?
by Bill Kramer
AutoCAD R13 introduces a new twist to the most powerful customization tool available for this CAD engine, ADS. In brief, Rx ADS changes the way AutoCAD and ADS-based applications communicate with each other. The net result of the change is greatly improved performance for ADS applications that communicate with AutoCAD frequently. One way of viewing the improvement is that Rx ADS stream-lines the communications between ADS and AutoCAD by eliminating the go between, which is AutoLISP in this case. Traditional ADS programs communicate with AutoCAD through AutoLISP, which, although fast, had room for improvement - especially in the arena of entity a table manipulations within the AutoCAD drawing database, an that is what Rx ADS addresses.
Rx ADS does not represent the quantum leap execution speed we experienced when ADS first showed up as a tool for improving AutoLISP, however it does point towards the direction Autodesk is taking us. Although we have not compiled any exact bench marks yet, programs running under Rx ADS show an improvement in throughput. The amount of improvement you would experience depends on the number of times a program makes calls to the AutoCAD system. One good incentive for porting to Rx ADS is that future releases of the AutoCAD APIs for other products will exist in Rx ADS before they exist in ADS. It is rumored that some libraries in the future will only be available to Rx ADS applications.
It was not easy to convert AutoLISP to ADS, and it won't be any easier to convert AutoLISP to Rx ADS. (Although in both cases, the gains in terms of speed may make the effort worthwhile.) However, updating existing ADS routines to work under Rx ADS is a very straightforward process. To give you an idea of the complexity, the only problem we had was in figuring out how to run the Windows Visual C++ programming environment properly. Which, by the way, is the programming tool you use to create Rx ADS programs. Our experience with programming environments has been plentiful, and the Visual C++ package from Microsoft is very nice. But it is also quite different from what we had worked with in the past, so it took some getting used to. The biggest advantage for serious ADS programmers is that the Windows NT Visual C++ program creates executable programs for NT, Windows, and DOS. That's because Rx ADS programs are DLL that are bound to the AutoCAD program. So far, our experiments have been strictly under Windows NT, but by the time of this printing, that situation will have changed.
Because Rx ADS programs are DLLs, they do not have the familiar MAIN entry point in a C program. Instead the function acrxEntryPoint() serves as the main program name. This entry point is used by AutoCAD when the load request is first issued, when a drawing is saved or loaded, and for other reasons much like the return values of the ads_link() function.
Rx ADS programs don't go away or just wander off between drawings either. Once an Rx ADS program is loaded, it continues to live between drawings. Event messages are passed to the Rx ADS application when the drawing changes; however, the complete program remains intact, and the only requirement is that function names defined using the ads_defun subroutine must be defined again when a drawing is loaded. Another nice feature of Rx ADS programs is that they can be loaded as AutoCAD is loading and actually begin to execute before AutoCAD is completely up and running.
All in all, Rx ADS is the right direction for Autodesk to be going. Using tighter communications between programs means that eventually more interactive gates will be opening up between AutoCAD and our programs. Of course, there is still a lot of room for improvement, however, Autodesk has done a very good job in not only communicating its intent with the developers but also in providing good tools to get the job done right.
Bill Kramer has more than 10 years experience customizing CAD/CAM/CAE systems. He can be reached at 7317,2635 on CompuServe's CADENCE forum or on Internet as (bill)@metrodata.com.
Recuadro: What's Hot? What's Not?
by John Wilson
One big, and certainly pleasant, surprise is that AutoCAD Release 13 replaces the Advanced Modeling Extension (AME). This change does not mean that AME has disappeared altogether, there is a provision in Release 13 to convert AME solid models into the new format.
How do Release 13's solid modeling capabilities compare with those of AME? They are about equal in their ability to create solids with primitives, extrusion, and revolution. All of the Boolean operations are in Release 13, but you cannot take composite solids apart as you can in AME. Release 13 can slice a solid into two pieces and is more flexible than AME in defining the cutting plane - but it isn't the same as separating a composite solid.
No special commands make fillets and chamfers on solids because AutoCAD uses the standard fillet and chamfer commands. Both of these operations work better than their counterparts in AME. They are intuitive and convenient to use, much faster, and can handle shapes that AME will not accept. Also missing, because they are no longer needed, are commands to transform a solid into a polyface form and back to a wireframe form. Now, when you invoke the hide or shade command, AutoCAD automatically converts solids to a polyface form.
Release 13 has a command for making a cross section through a solid, just as AME has. The resulting entity is a region, so data on area properties is readily available. Some of you, however, are likely to be disappointed to find there are no other commands for making 2D images from a 3D solid.
3D Wireframe Construction and editing
Some new features for 3D wireframe construction and editing in Release 13 are unspectacular but important. Most of these new features have been borrowed from AutoSurf, Autodesk's sophisticated 3D surface modeling program released about one year ago.
In previous versions of AutoCAD, entities had to be in a plane parallel to the User Coordinate System (UCS) before you could fillet, chamfer, trim, or extend them. Now you can perform these operations no matter how the entities are oriented within the UCS. Trim and extend can even be view-dependent entities to be trimmed or extended, but they do not have to be in the same plane as the boundary. Break also works better. Breaking entities that were not parallel to the UCS has been an uncertain operation in which AutoCAD reflected the selected break point off of the UCS so the entity was actually broken at another location. Now, an entity is broken at the pick point.
Picking overlapping entities, which commonly occur in surface models, is easier. You can now hold down <Ctrl> as you make a pick, and AutoCAD will select the bottom-most entity and highlight it. If this entity isn't the one you want, continue to pick on the stack as you hold down <Ctrl>. AutoCAD will work its way up until you accept an entity or until it reaches the top, in which case, it will cycle back to the bottom. This feature is especially useful for those commands (such as rulesurf) that won't accept a window or a crossing selection.
Release 13 has a command, named group that allows you group existing entities together with a name. Then, you can use this group name to build a selection set. Members of a group do not need to have anything in common, except that you want them to be grouped together. Groups will be useful when you are working with a crowded 3D model.
A new wireframe entity, which goes by the name of spline, is similar to a 3D polyline in that it has zero width and it can twist and turn through 3D space. Unlike a 3D polyline, it is always smoothly, curved. Splines can be trimmed, stretched, and broken, but there is no provision for moving their control points. The new spline ellipse will also be useful for wireframes because you can draw just the section of the ellipse you need. You'll no longer have to draw a complete ellipse and then trim it to obtain the portion you want.
John Wilson is a mechanical engineer with over 15 years experience. He is the president of Computer Based Drafting in St. Louis Park, Minn.
Recuadro: What's Hot? What's Not?