Spaceclaim for the SolidWorks user
Spaceclaim may be as conceptually difficult for SolidWorks users to get their head around as SolidWorks is for AutoCAD users. Conceptually, these are two different beasts. Not different like SW and SolidEdge, but different like oil and water.
Before we get too concrete, I just want to state some of the facts around the topic. Spaceclaim is a new CAD venture by parametric modeling heavy weights Mike Payne and Daniel Dean, both founding fathers of PTC. Mr. Payne was also a founder of SolidWorks. They are banking on the belief that “parametric” and “history based” modeling have limitations in the ease of use and complexity, and that it is too easy to build yourself into a corner which you can’t get out of easily. This is a major change in direction for these two because they were instrumental in developing the whole parametric history based design paradigm in the first place, and here they are developing a product which rails against parametric history based design.
Spaceclaim claims that 80% of the product development team is excluded from using CAD due to the need for trained specialists to run the parametric modeler, but that these non-specialists often need a way to work with model data. Spaceclaim puts CAD into hands of non-specialists. They believe that the place for their software is alongside parametric systems, not as a straight replacement for something like SolidWorks. Spaceclaim might also go into places where a tool like SolidWorks might never be used such as on a machinist’s or manufacturing engineer’s desktop. SolidWorks apparently sees things differently, because they do not allow their resellers to also handle Spaceclaim. Spaceclaim claims not to be competing with SolidWorks, but SolidWorks is clearly competing with Spaceclaim. I don’t see how the same person would use both tools, or how Spaceclaim would be useful upstream from a parametric modeler in any development workflow, unless it is used as a concept modeler, with the parametric tool being used as the production modeler.
Especially in the 2008 version of SW, you may notice that SolidWorks seems to be trying to emulate the functionality of direct geometry editing, but they have to do it in the confines of a history based framework. This gets confusing sometimes because you are using tools that are meant to be non-parametric in a parametric setting. This review is not a feature-by-feature comparison, it is a comparison of philosophy and underlying modeling/editing concept aimed at helping people who have grown up in a parametric world see that there is another side to things. Parametrics are often very powerful, but the downside to that is that they are often very cumbersome. How many times have you been able to see geometrically what needs to happen, but the parametrics won’t let you change it the “right” way, so you need to cheat, or do something the SolidWorks best practice police wouldn’t approve of. Editing geometry directly without concern for process, can be very liberating.
To be clear, by “non-parametric”, I mean the lack of ability to change a model using a sketch that drives a feature, or by using numbers (parameters) in a dialog box. Parametric modeling is typically associated with history based modeling, because to store parameters, you have to have identifiable features, which must be put together in an identifiable order. Some examples of non-parametric modelers are Sketchup, AutoCAD solids, CoCreate OneSpace, Rhino, and so on. Some times the word “non-parametric” is replaced with the term “direct modeling”, in that you edit the geometry directly, not though a set of parametric numbers and relationships. Even SolidWorks has a little experience with non-parametric modeling in the guise of Cosmic Blobs. Parametric modeling enforces a structured process, while direct modeling simply allows you to be concerned about the existing geometry, and changing it, rather than how the geometry was made.
Spaceclaim can create parts from the ground up starting from sketches using lines, arcs, ellipses and splines, but is equally at home editing existing parts. In fact, editing existing geometry seems to be where most of the emphasis is put in the demonstrations I have seen. To take it a step further, in Spaceclaim, editing is a creation method. Notice in the interface that the only tools used to “create” anything are the Sketch tools. The Edit tools are where most of the action is.
The first thing you notice about Spaceclaim is that the interface has almost the identical look as the new SolidWorks 2008 interface, which is itself copied from Office 2007, however you feel about that. This follows right down to the function of the context toolbars and RMB menus. The interface is not what concerns me here.
You can open several kinds of files with Spaceclaim, including SolidWorks native. I have to say that opening a complex SW file was a pretty slow process, and the graphics aren’t there 100% yet. I’m using a laptop, processor: AMD Athlon64 4800+ dual core, video: nVidia FX Go 1400, memory: 2 GB. Pretty nice 1.5 year old laptop for SolidWorks.
Spaceclaim, like Alibre, is based on DirectX graphics rather than OpenGL. This has a couple of important implications. First, the expensive CAD video cards we’ve been accustomed to buying are not as necessary with Spaceclaim, and Spaceclaim is not as hampered by the Vista OGL video driver debacle as are SolidWorks and other OGL dependent programs. Of course this also means that Microsoft wins this round of the “my video standard is more standard than yours” chess match.
From the Spaceclaim website:
Radeon and GeForce on the recommended list? There is nothing spactacular or eye catching about the graphics in Spaceclaim, but the possibility of saving at least several hundred dollars, possibly a couple thousand on video card per computer is definitely appealing. Could you live without RealView? Spaceclaim will never be known as an effeminate CAD system.
On a side note, John McEleney said at the Charlotte user group meeting that SW is using a new “benchmark” for graphics speed, and it is not other CAD systems, as it has been in the past. He spoke of Xbox gaming graphics as being what SW is now measuring itself against. This brings up some questions about the future of OGL for SolidWorks. I think I will hold off on buying the latest and greatest $2500 OGL CAD Workstation graphics card. The situation and the rest of the industry make it look like DirectX is the new direction for CAD applications, regardless of how you feel about Microsoft bullying tactics, on full display in this arena. I believe we are seeing another nail in the coffin for both Mac and Linux based mechanical CAD.
While we’re on this tangent, it is significant that this brand new CAD system only tuns on Windows. Along with Alibre and even Rhino, no major new CAD system (except modo) is moving to Mac or Linux. TurboCAD, Ashlar-Vellum, modo, etc… for the mac, and a few for Linux too already exist. Some of these are as old as ME10, Microstation 95 and even Medusa!
Ok, back on track here. Spaceclaim doesn’t use a part origin or even sketch relations. Sketches disappear after they are used to make solid geometry, and are not listed in the “Structure” tab or even accessible. There is no history tree, and no list of features. In fact, there are only about a dozen actual tools to edit geometry. This is probably why most of the focus is placed on editing rather than creating.\n\nThe main tools used in SC are the Pull and Move. You can think of Pull as being like a combination of extrude and revolve. It can add or remove material. It can create surfaces or solids. It doesn’t use any of that terminology, though. Imagine using SW by using only the Move Face, Delete Face, Fillet, Shell, Split, and a single tool that extrudes and revolves, bosses and cuts, solids and surfaces. And that’s it. You can’t make the wildest swoopy parts, although there are spline and sweep tools. Still, you can edit imported prismatic parts even with draft and fillets with the best of them.
Fillets in SC are a dramatic improvement over SW in some ways. To appy a fillet, you just select an edge and pull an arrow. You can even pull one end of the fillet to make a variable radius.
Spaceclaim uses surfaces, but in a much more intuitive and yet less direct way than SW uses them. In SW, you must be very explicit about everything. The advantage of being explicit is control. In some ways SC may be seen to allow less user control, and in other ways it allows more. Spaceclaim automatically uses surfaces as reference geometry used to edit and create solids. For example, in SW we create “thin features”. In SC, they create a surface and thicken it, but not conciously as we do in SW, you just Pull a line to make a surface, and Pull a surface to make a “thin feature”. You don’t tell it what to make, you just pull it. In SC, symmetry is set up and applied to solid model faces rather than to sketch geometry.
The Shell function in SC seems far faster than the equivalent in SW, as well as the ability to remove multiple faces, even tangent faces. The old demo trick of turning a cube into a sphere by using fillets in SW is far surpassed by SC because it leaves no edges on the resulting sphere. Plus, the sphere can be changed in size without the fillets failing. SC does not seem to have the ability to do multithickness shells, and is still susceptible to the problem of a large fillet on the outside applied after the shell causing the inside of the part to show through.
SC does not have a complete arsenal of complex shape modeling or editing tools. It cannot, for example, tug and pull on U-V points on a surface like other direct modelers such as Rhino. SC does, however have two advanced creation/editing tools. First, a Pull can be done along a non-linear path. In SolidWorks, the equivalent would be a sweep feature.
The second tool which deserves more space than I have for it here, is called Edit As Blend. To over simplify it, it would be equivalent to a SolidWorks loft, but different in important ways. For example, you can create an extrusion, create a blend plane in the middle of it, and change the cross section by dragging the size, and blend the new geometry into the old.
In essence, the method of editing has absolutely nothing to do with the method of construction. A shape can be created by revolve and then the individual faces can be moved off axis if desired. Planar face can be bent into curved faces. If a face is consumed in an edit, the face will not return in subsequent edits, unless the subsequent edits are undos.
The Spaceclaim business model is controversial for some. They don’t hand out evals, but then neither does SolidWorks. Deelip thinks this is bogus, but having been on the reseller side of things, I would much prefer that someone come into the office to run the software with someone available to answer some questions. People who sell software simply don’t trust people who use software to answer their own questions. I agree with Deelip that evaluating software using your own data and your own way of doing things is important, but I would never eliminate a software package based on my own ability to simply figure out how to run it from scratch.
Even more controversial is the “rental” model. There is no up-front software cost. It is run by subscription fees. When you end your subscription, the software turns into a viewer, it will no longer edit. That part of it is certainly a bummer. The rest is pretty good, though. If you consider that it is like buying SolidWorks, except that you only pay for the maintenance. Deelip, being a programmer, has a better handle on the internal file goings-on than I do, and his analysis of the native file type being basically a binary ACIS file is very interesting, especially in the light that nothing available seems to read or write binary ACIS files.
Anyway, so who would use this software? It is my guess that SolidWorks users are not going to want to use this software. Although it reads native SW files, SC does not write feature-based SW native files. The only way to go back is through some imported dumb geometry format. I think people at the bottom of the data food-chain will wind up using it: machinists, mfg engineers, and so on. While some of the changes you can make are very liberating compared to parametric systems, you also will gain a new appreciation for exactly which benefits come from your parametric tools.
Is this the next big thing in CAD? No, it is old news, really. Better dressed possibly. Better managed, easier to use, more accessible, more powerful, but non-parametric CAD has been around longer than parametric CAD. Will SW users be dumping SW for it? No way. Not yet. If it gains some capabilities in the NURBS surfacing arena, I might become interested to use it as a quick editor, but even so I would want to just purchase outright a license that would collect dust for the most part, except for those isolated life-threatening situations where you absolutely need it now.
It does raise a question about CAD best practice. Once you move a model to SC, you cannot move the changes back into your parametric system. For mixed environments, this is going to cause the design side some frustration because their models are not kept up to date with changes. Those awful markups that manufacturing people make on the floor, and the need for change is not communicated back to engineering are just going to get one step worse.
I hope to see a great application for this tool, because it is a very cool tool, and in the right situation will be very useful. On the other hand, I fear that it is just going to become another instrument in the breakdown of comunication from mfg to design.