Direct Edit, SolidWorks, Instant3D, and Move Face

instant3dmovefaceThere is a good discussion going on about Direct Editing technology between Paul HamiltonDeelip,Ken WongRalph Grabowski, and CEOs of Think3, Alibre, a founder of Spaceclaim, and a lot of other folks on a number of different blogs. I think now that Spaceclaim has been around for a while, and Synchronous Technology has had the opportunity to make the rounds, the discussion has a bit of a baseline this time. Some of the pedants are not involved this time, so I think it is a more rational conversation. It’s a good conversation, and it covers a lot of ground, so I don’t want to rehash it all for you. I think it was spurred by the nearly simultaneous press releases about Autodesk Fusion and SynchTech2.

There is still a bit of misinformation, though. Some people are using the words SolidWorks, Instant3D and Direct Editing all in the same sentence, and these people aren’t SolidWorks users.

It’s interesting to me the people who have NOT shown up for this discussion. SolidWorks allows its users to be their voice in web discussions. How interesting. The user group guy who claims the title “SolidWorks Evangelist” doesn’t seem to believe in the web. The SolidWorks people who believe in the web aren’t users. The users who believe in the web and participate in these discussions get excommunicated by corporate. I’m not sure if any word other than stupid really characterizes SolidWorks lack of participation in discussions of this sort, and the web in general. Look at the army of (paid) bloggers Autodesk has fielded. SW has web people on staff, but they are web community developers or web marketers, they don’t really have any web technical personalities. Gohere to see how many web technical personalities Autodesk has.

I’ve talked with some SW people about direct editing topics, and the only way I can characterize their side of the issue was that they don’t feel any sense of urgency. Now maybe I was talking to the wrong guy (I wasn’t), but I don’t think SolidWorks is not going to go out and turn the software on its ear just because Solid Edge and NX did. I don’t think they will build a new product just because of Fusion (how many failed modelers is Autodesk responsible for?) I think SW will just enhance some of the tools they have, and it will be maybe 3 enhancements of the typical 150 that come every new release. 2010 beta is literally days away, so we will see shortly what the immediate future holds.

instant3dintAnyway, back on topic. First of all, Instant3D is NOT direct editing. Instant3D is an interface gimmick, using parametric methods on a purely history based model. The fact that it looks like direct editing is entirely coincidental.

When you use Instant3D to change a part, you are NOT making direct edit type of edit, you are making a parametric, history based edit. Granted, you are skipping some of the less desireable aspects of history based edits like having to unbuild and rebuild the model, but I assure you, that is still happening behind the scenes. The fact that the interface looks like a direct modeling interface and that it has fooled even some bright people into saying this compares to Direct Editing is probably good news for the spin marketing group. They will get the credit for doing direct editing without doing the work.

Instant3D does not add features to the tree because it is just editing features that are there. It does require rebuilding the model, including features that come after the feature that is edited with Instant3D. This is the main difference between Instant3D and Direct Editing, especially in light of SynchTech’s claim to be 100x faster in certain types of changes (due to the lack of rebuilds). Where direct editing actually has an advantage, you shouldn’t take it away from them.


The Move Face feature in SW does create a feature in the tree. I’ve said a lot of times, along with some other respected users, that Move Face is a cheap and dirty tool. It is not on any best practice lists except when dealing with imported geometry. But sometimes it can get you out of a modeling bind. Having this tool available is a definite benefit to users. Move Face would be a direct editing tool if it did not create a history-based feature in the tree. So again, almost direct edit, but not quite. It has the direct edit advantage that it doesn’t matter how the face was created, you can just move it, but it doesn’t have the direct edit advantage that there is no tree to rebuild.

instafaceInterestingly, you can combine Move Face with Instant3D, but look at what happens. It starts measuring the Move Face feature at the end of the initial extrusion. It is just allowing you to drag the face offset distance. Again, it’s a bad idea to mix this with regular parametric modeling if you don’t have to because of stuff like this.

Part of the discussion was about is it “Direct Edit” or “Direct Modeling”, and someone made the argument that rather than giving us a new way (old way really) to edit stuff, why not just a new way to create stuff? Somewhere in there, I think someone got boolean modelers confused with direct editors. Well, I believe in the addage that says “create something once, edit it a dozen times”. And that’s really true, not just because of flaws in CAD tools that don’t allow us to create what we think, but because of flaws in our design and business processes that seem to always require something different, regardless of where we start from. I think tools for editing are great. That’s what I need most.

Anyway, if there is one use for Instant3D I like best, its the use with fillets.

You can grab the blue ball on a fillet and drag its size. That, if nothing else, is brilliant. I’ve always dreamed of a macro


that would maximize fillet size, and this is the thing that comes the closest.

Fillets are really one of the whole direct editing schemes biggestfilletalt downsides. There are some inherently history based things that fillets do, but I haven’t seen any of the direct editors handle these yet. The image above shows how the FilletXpert in SW can create fillet intersection/overlap options.

I have to admit I was impressed with how SynchTech handled shells, basically as a wall thickness. This has advantages and disadvantages over the history based method. The big advantage was that it enabled you to shell selectively, where doing that is a huge difficulty in history based systems. Still, I don’t think that it is a limitation of the technology, just a limitation of the current implementation in SolidWorks of the Shell feature. I’m confident SW could make Shell to shell selectively if they wanted to.

What does it all boil down to? I think there are some people who believe that these direct edit only products (Spaceclaim, Fusion, CoCreate, Solid Edge wST) are going to take over CAD. The rest of us seem to believe that the future will look more like the present, but with more direct editing options in our history based parametric modelers. The critics say that Alibre and SolidWorks are left out in the cold right now because they are the only ones now waving direct edit banners. According to some, SolidWorks is being hampered by Catia’s reluctance to share the direct editing tools in V6. That may or may not be true, I don’t have any idea. I thought Jeff Ray was brought on to make SolidWorks a lot closer to the DS parent. If they wanted to keep SW at arms length, they should have kept McEleney.

I would like to see changes to history modelers that are much smarter than the current generation, where it treats the geometry like dumb (direct edit) data until a change is made that requires a rebuild. I think that some smart folks put their noggins together, there is a solution that combines the best of history with the best of  direct. SynchTech certainly isn’t it with its toggle approach (a part is either history or ST, not both). I think SolidThinking has some very interesting solutions which I wish some of the mainstream people would comment on, or dissect a little bit.

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