Cadalyst MCAD Tech News #119 (April 15, 2004)

14 Apr, 2004 By: Joe Greco

If you're like me, you may have read many positive statements about IMSI's TurboCAD 10, some going so far to compare it to MCAD modelers such as SolidWorks, Inventor, and Solid Edge. When I received a brief demonstration at COFES two weeks ago, I too was impressed with some of the new commands I saw. Then last week, I received my evaluation copy from IMSI. The box listed many more of the program's top features. A few caught my eye, such as Historical, Editable Part Tree and 3D Shelling, Lofting and Blending. Eager to learn more, I installed TurboCAD 10 that same day.

GETTING STARTED
Installation was simple. All that's needed is to input the serial number found on the envelope that holds the CD. When TurboCAD 10 opens, a fairly standard Windows user interface appears. The software displays a lot more tools than most products, which generally attempt to keep things simple. After using the product a while, I found, as in past versions of TurboCAD I've used, that frequently these tools could be better organized.

For instance, the main toolbar is called Drawing, which implies 2D features, but it also houses tools for 3D creation and editing, lighting tools, and more. In addition, each tool has a fly-out toolbar that reveals, on average, about eight more tools. Most programs with modern user interfaces long ago abandoned this fly-out strategy and replaced the numerous tools with a single icon that represents all the related tools. Once selected, the tool's commands are displayed as options in one way or another, depending on the application. This technique ensures that no tools are buried and perhaps more importantly, that the tool's icon never changes, as it does when fly-outs are employed (this can be very confusing to new users).

Of course you can avoid the fly-outs by having TurboCAD 10 keep each toolbar open, but this crowds the screen with 61 of them. This is in addition to the 16 palettes that can be squeezed on the right side of the screen to organize everything from symbols to materials to drafting views (but not layers, for some reason).

CREATING OBJECTS
I started with TurboCAD's 2D tools. As you can guess by now, there are lots of them, including 13 ways to draw an arc. Half of these are related to snapping conditions and could be eliminated. Other tools draw splines, Bezier curves, and more. At first I found the snapping to work a little strangely - for instance, when the Vertex snap is turned on, that's all the program looks for. The key is to turn on the Use Mouse Position option in the Drawing Aids window- then a free point or a snap point can be located. Only when I turned on the Extended Ortho and Apparent Intersection snaps did the program display the dashed alignment lines most applications today have turned on by default. Once they are turned on, they work quite well.

Once you create some 2D shapes, it's possible to create solids and surfaces. When a closed shape such as a rectangle or circle is extruded or revolved, a solid is created. Meanwhile, open shapes such as splines become surfaces. TurboCAD has a Loft tool that works like a breeze, but lacks advanced options. I also had difficulty setting up the initial shapes to loft. For example, I created three curves on the same plane in the top view and then tried to reposition them in the front view by dragging. Sometimes this worked and sometimes it didn't. As it turns out, the only way to get it correct is by keying in the values, but of course you have to know to display the x, y, and z positioning options in the Selection toolbar located at the bottom of the screen.

Unlike most 3D programs, TurboCAD houses 3D primitives that make the creation of spheres, cones, cylinders, torii, and other shapes really easy. No matter how a 3D shape was created, it's possible to simply click on it to reveal handles that you can use to move, rotate and resize it (these also appear on 2D entities). In addition, any 3D object can be edited by either using a pair of free-form deformation commands or feature-based tools such as Fillet and Shell.

EDITING OBJECTS
I commented on the two free-form deformation tools in my brief mention of TurboCAD 10 in the last issue. Actually using them turned out to be a good experience. Though the sculpting is a little difficult to control with dragging and there are other limitations, the two deformation commands proved impressive for a package costing only $795.

The 3D fillet is fairly powerful, but unfortunately most of its advanced features, such as a variable radius and setback options, didn't work in this released product. The program did handle a complex corner fillet where all three radii were different. The Fillet tool also includes chamfering capabilities, which created an asymmetrical condition without a problem. The Shell command worked fine, though I didn't test it with any complex shapes. Both the Fillet and Shell would benefit from the addition of a Preview button.

Another highlighted feature on the box-the Historical, Editable Part Tree-is a misnomer. TurboCAD doesn't have a history tree; it just keeps track of the features added to separate objects. For example, I created a rectangle, extruded it, and then added a fillet. The Part Tree palette, which is not turned on by default, showed the object's hierarchy with the fillet listed on top followed by the extrude with the original rectangle shown below that. However, only the fillet can be edited (theoretically, because that didn't work either). The extrusion can't be changed. The 2D rectangle it is based on can be changed, but this doesn't update the 3D object.

Next I shelled the part and found that editing this feature did update the model. But when I deleted the previous fillet feature to see if the model would update, the entire part disappeared! After an undo, I created a new workplane on the top face and built a cylinder there, but TurboCAD sees this as a separate object with its own tree. Also, as expected, there is no way to change the order of the features.

Also located in the same toolbar as the Fillet and Shell are three Assemble commands. However, they are not like the assembly mating commands found in MCAD products like SolidWorks-they simply move and align components. IMSI should consider renaming these tools as such.

2D SHINES, 3D NEEDS WORK
TurboCAD 10 features numerous new 2D drafting options, many of which I outlined in my previous newsletter. In short, as a 2D program, TurboCAD 10 does fine. If that's all you need and don't want to be part of the Autodesk world, it may be a better choice than AutoCAD LT. IMSI is a member of the Open Design Alliance, and its product did a good job opening several test DWG files, retaining the layers, colors, dimensions and so on.

As an alternative to SolidWorks and the like, all I can say is that if you can do without 2D constraints, powerful 3D solid modeling, real surfacing tools, assembly modeling, advanced interoperability tools, sheet metal, and a bunch of other stuff, TurboCAD may work for you. If you can't, don't even bother evaluating TurboCAD 10.

A more valid comparison is between TurboCAD and VectorWorks, which is also currently at version 10 (v11 is coming soon) and priced about the same. I believe VectorWorks has a better user interface (even though it does need work), about equal 2D tools, and far superior 3D commands, with some surfacing options that come close to Rhino's capabilities. IMSI is trying hard, but it's difficult for me to find a niche where its product excels. Also, it's hard to believe that several commands didn't work while others were inconsistent in their operation. TurboCAD 10 provides a lot, but needs more work.