Synchronous Sketches with Ordered Features

This is a topic that some may initially find a little esoteric, maybe even dull to some. But I assure you, it has big implications. If your favorite history-based software had this sort of functionality, you might feel better about history.

In history-based modeling, you usually think of sketches as being history-based too. Not inside the sketch, but each group of entities grouped as a “sketch” has a certain order, and can even have parent-child relations with other sketches. In some of my posts on the Dezignstuff blog about how to improve history-based  modeling, I suggested that a single sketch environment that wasn’t split up into separate “sketches” would make more sense and be easier to edit than the current deal where you get “out” of one sketch and “in” to another. This slows things down so much.

Plus, here is something that just drives me batty. Within a sketch, order doesn’t have much to do with anything. But between sketches, order has everything to do with it. So you’ve got this weird thing going on where sometimes you have to think history-based parent/child thoughts, and sometimes you don’t have to worry about that. It’s the same thing between parts and assemblies. Within a part, all your features are history-based, but in an assembly, you don’t worry about history. In fact, thinking history can get you in trouble. Except sometimes when you have history-based features within the assembly. So In SolidWorks, you’ve got this confusing layer cake of History, and Not History:

  1. within sketches: No
  2. between sketches: Yes
  3. features: Yes
  4. between parts: No
  5. mates: No
  6. incontext: No
  7. assembly features: Yes
  8. mates to assembly features: Yes

How do you keep all of that straight? Really? The thing is you don’t. Or most people don’t. They might add fillets or draft to a part, and it completely blows up in-context features or mates in the assembly. If assemblies were history-based, you’d never be able to make changes that made sense. Ay.

“Synchronous sketches” in Solid Edge just mean that the Yes after “between sketches” above at #2 becomes a No. “Synchronous sketches” in Solid Edge means that all the sketches exist together all at once. Not one before the other. So when you edit one sketch, half of them don’t disappear. One of the problems with history modeling is that is is so one-directional. You can only go forward with it. Making your sketches synchronous means that you can make relations to any sketch from any sketch, regardless of order.

In addition to Synchronous sketches allowing bi-directional interaction, Solid Edge also has what is known as the Blue Dot. The Blue Dot is an entity that transcends time and history. If you have a mesh of history-based sketches, you can use a Blue Dot to allow those sketches to react in a non-history based manner. This Blue Dot thing is cool. Especially if you do any surfacing in Solid Edge. I’m getting an example together to demo this a little.

Updated: April 27, 2012 — 5:11 pm


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  1. Ok so I’m getting the idea. Really Synch ought to be very useful for ID work. They just need to give us some extra surfacing tools to exploit its benefits. I’m going to hold out on those UI changes too rather than be frustrated by the sock drawer. SW still gives every indication its in self destruct mode so lets get ambitious and say SE could pick up 250,000 users many of whom will have some ID purpose. It ought to be worth hiring a small dedicated extra team of people working to tune and realise SE’s potential for our purposes. Existing SE users ought to benefit from the cross pollination of experience too.

  2. Neil you really think SE will pick up 250,000 users? The elephant in the room of that assessment is those 250,000 users will need to buy SE rather than update SW (or any other system they might be using). The only way SE will achieve this is to offer a competitive upgrade route costing around the price of a year’s subs of the other systems. I know from comments on other forums and directly talking to others that SE has offered these deals in the past – in much the same way that Autodesk’s growth in Inventor seats is due almost entirely to cheap upgrades from Autocad. So maybe it is feasible.

    Personally I doubt SE will ever develop the surfacing tools much more than they are already. Adding too much surfacing will impact on NX sales. Ask any reseller who sells Se and NX and say you to product design – they try to sell you NX, to the extent that they play down SE.

    The general opinion of all the big companies is that fancy surfacing is specialist and only happens in “enterprise” businesses who can afford £20k a seat. As we all know though, that attitude is a load of rubbish. 1990s thinking.

    1. The general opinion of all the big companies is that fancy surfacing is specialist and only happens in “enterprise” businesses who can afford £20k a seat. As we all know though, that attitude is a load of rubbish. 1990s thinking.

      AAAAARRRRGGGHHHH! This drives me nuts. There is no logical connection between shapes and size of business. This is why I am so convinced that usable, high-quality shape concepting and product development tools are going to make it into the mainstream. Concepting stuff is already there in the form of subd tools.  I would really like to be able to create the shapes in the same software I use to do the part engineering.

      I’m less sure that SE won’t develop more usable surfacing tools. A couple years ago I was sure they wouldn’t, but now I think they might. The advantage of NX over SE is of an entirely different sort than just the types of geometry or types of products they make. I think the basic difference is in the complexity of the project, and the complexity of the business behind the project. You might not design a space shuttle in SE if for no other reason, just because of the complexity of the overall project. Not due to shape, not due to size of assembly. I’m convinced mid-range is as entitled to shape creation tools as any other level of software. Shape creation is slow to becoming the same sort of commodity that basic solid modeling already is, but it will get there one day. With the Parasolid kernel, there is no reason SE can’t create great shapes.

    2. Probably they are right to show you NX because SE really isnt focused on ID work. I would call that technically honest and a good customer service. We know SE currently doesnt have the same capability as SW but thats largely a marketing choice to specialise in mechanical stuff rather than a lack of kernel capability. I think its really up to Siemens to decide if they want to pick up on Dassaults blunder. In a pure $ and ¢ consideration it does seem like it could be a once in a lifetime windfall. Its not like they have to convince people to move from to 2d to 3d or something. Its more a mature group who know what they want but cant buy it anymore, like a car with bench seats, and in looking elsewhere find the another manufacturer does make that and actually has some unique  cool stuff of their own, like a solar powered can cooler. To me it makes good business sense to get out there make a public statement of intent and start giving SE some ID tools. 250,000 users might well be attracted to an enhanced SE to replace SW, and yes perhaps with the incentive of some tradein sweetener – that would be clever marketing, whereas say maybe 2500 would be in a position to trade up to NX really for the same reason they didnt buy Catia originally. I dont think they would be canabalising NX sales at all.

      1. Thinking about this some more let me put it this way – There is a decent prize to be had here. If Siemens are prepared to put a bit of effort into meeting new ID users half way then everyone can benefit. Really that half way probably only amounts to about 15% extra work initiately to accomodate slightly different needs and those needs would benefit existing users as well. The more they can do the more business they will attract. If there is an attitude that any refugees can just learn to fit in and make do with what is already available then its going to go nowhere for them and we are wasting each others time. If we hear things like ‘everyone loves our ribbon UI’ when we say ‘it doesnt flow for artistic purposes’, or we hear ‘if we give you internal spline point control you will only get into trouble’ when we say ‘we would like to have this’ then it reasonably obvious SE are only really thinking about trauling for a minimal number of defectors and this blog is something of a pretense, which would be one fast way to kill my participation. ;)  Without wanting to belabour the point too much disaffected SW users have had enough of companies who arent responsive to their expressed wishes and serve up things that they believe are a priviledge to buy. ok off soapbox.



    3. What a sales partner chooses to target for your account is obviously up to that partner (and you!). However, what I can tell you is there is absolutely no ceiling placed on Solid Edge with respect to functionality and infringement on “NX territory”. There never has been, nor will there be. I can tell you factually that we each make our independent decisions based on our markets (which frankly don’t overlap as much as you might think).

  3. those 250k seats of solidworks includes 150k (i think) at various universities.

  4. Yah way are sketches history based in assembly ?

    It is kinda a pain when you re doing layout work.

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