Displaying constraints intuitively in Synchronous mode: Possible?

Hey there, I enjoy Synchronous mode's workflow in many ways but still can't really use it in day-to-day work. I work with designs that are very sensitive to having correct geometry (think medical devices), so it's very important that a given drawing is fully constrained. This is for a couple of reasons - obviously, to guarantee a lack of ambiguity once it goes to manufacture as well as that feeling of having the design "locked" in. Hopefully this will persuade you that I have genuine needs for verifiably fully constrained parts. This is not only for me, but to assure others that a particular drawing is unambiguously defined.

Now, I do understand that it's possible to fully constrain a Synchronous part, but it's very hard for me to intuitively grasp what is and is not "locked" in while I'm modelling a complex part in the same way as Ordered mode. I can obviously guarantee that dimensioned edges are what they've been dimensioned as, but on a complex piece it's nigh impossible to tell if everything's taken care of.

In Ordered mode, I normally use the function to colour lines based on constraint to be able to tell if something is constrained at a glance. Is there an equivalent tool or function I could use for Synchronous modelling to make constraining more intuitive on the model? Say, like colouring in fully constrained faces?

Such a feature would mean I could confidently apply Synchronous Modelling to day-to-day workflows.


Re: Displaying constraints intuitively in Synchronous mode: Possible?

No offence meant here but I think this is your issue and not one of the software.  Unless you change the sync part then it will be as designed.  There is just as much chance an ordered part will change due to in built relationships, possibly more.  In Sync those are more visable during any edit.  Maybe I am not understanding your issue fully?


If you have things manufactured then is that from a drawing?  If so then the drawing must be chacked prior to being sent to the supplier?

CAD/CAE Manager
ST8 MP12

Re: Displaying constraints intuitively in Synchronous mode: Possible?

I think @Guy_H77 is hitting on the uneasiness we all feel about Synch as "Ordered" experts.  With an ordered sketch, undercostrained elements would often change in unpredictable ways even when those elements weren't directly edited, so we learned to lock everything down as a necessity.  Synch is different in that un-selected faces do not move unless you have built a locked dimension or a persistent relationship to those faces from the faces you have selected to move, thus it is predictable and the old "rule of thumb" of locking everything down no longer applies.  It definetely takes a mind set change...


Production: ST9 MP7
Testing: ST10

Re: Displaying constraints intuitively in Synchronous mode: Possible?

Well, that's just the thing. I'm not asking for a substantial change in functionality, I'm asking if there's an easy way to visualize the functionality that's already there. I know it's possible to keep a synchronous part in check, it's just that I have difficulty verifying that's the case, or persuading someone that the model I've defined has been thoroughly dimensioned. 


I'm trying really hard not to indicate that I think Synchronous is ACTUALLY less reliable than Ordered mode. That's not the issue. It's just that I can't visually determine how reliable or thorougly dimensioned a model is as I work. Most of the time it's probably fine, but I'd really like to be able to verify that.

This is really a workflow question, not anything much deeper. I use the constraint colouring system to make sure I've explicitly defined all dimensions when creating a model. I'm trying to find a similar to visualize constraints for Synchronous mode. Or perhaps worded differently -I'm trying to find a convenient way to make sure I've explicitly defined all possible dimensions.

Re: Displaying constraints intuitively in Synchronous mode: Possible?

I understand that it may be predictable, and that for modelling purposes I really don't need to lock it down. But both of those things are a little beside the point. It's not about how predictable the changes are, it's about being able to tell at a glance if I've thoroughly defined everything. I usually used constrained colouring as a sort of self-check to make sure nothing has been left unexamined or undefined - I'm simply after a similar functionality.

It's not that I don't believe that Synchronous is "safe", it's that I don't necessarily trust myself to have properly defined dimensions in extremely complex and sensitive models. I'm looking to be able to make sure the model has been explicitly dimensioned for all features. Or, more accurately, I'd like to be able to see which features are explicitly dimensioned and which aren't. This way, I can make sure important geometrical fits have been fully defined and fixed (i.e. geometry that cannot be changed no matter what) whilst having the remainder of the device stay "flexible".

I feel like the answer I'm getting is that such a feature doesn't exist in the standard ST9 software, though.

Re: Displaying constraints intuitively in Synchronous mode: Possible?

[ Edited ]

@Dskel, I agree with you that this is a problem. I've experienced what I call "feature drift" in synchronous. While changing some part of a model which has many small features I sometimes find later that some face or faces have gone out of parallel or perpendicular by a very small angle which can only be detected by close zooming. Also sometimes features not observable during the change have disappeared. There is no way to tell what will not move. You can make rigid sets but sometimes that prevents changes you want. It would be useful IMO if there was a capability to visually tell what faces are constrained that would color all faces that are fixed, or coplanar, or not constrained at all. But then sometimes you need to turn off, say, coplanar, in design intent in order to make a change, then having that off allows small features to drift. I don't know, maybe this isn't really possible to do with synchronous because it's too dynamic, especially with design intent switching by the user, to pin down.

Then again, my problems may lie only between the keyboard and chair.

Bruce Shand
ST9 MP8 - Insight - Win10 - K4200

Re: Displaying constraints intuitively in Synchronous mode: Possible?

I agree that this is a problem with sync. Sometimes the model is too complex too see everything that will change due to design intent settings and assigned constraints and PMI. If features are too small or far removed from your area of focus they can change in imperceptible ways - a very slight angle on a face that was normal, for example, or disappear altogether and you may not notice until later. And by that time an undo is impossible.

It's true that things can go wrong in ordered as well but because features are discretely controlled by sketches the problems tend to be confined and usually alerted to by errors. Whereas with sync the entire model is dynamic and subject to subtle changes which the software doesn't consider errors. It is not easy to know what is locked down and not subject to change.

Bruce Shand
ST9 MP8 - Insight - Win10 - K4200

Re: Displaying constraints intuitively in Synchronous mode: Possible?

I had always wanted to have a built in model compare in part modeling.

A feature where you could open a file and click "Create Graphics Snapshot".

Just the OpenGL graphics. Not geometry.

And when you were finished editing you could "Compare Model To Snapshot".

This seems like would be valuable in Ordered and Synchronous mode.

And also help new users get over that fear that they inadvertently edited the model in a bad way.

Anyone else think that would be a good addition or just me?


Re: Displaying constraints intuitively in Synchronous mode: Possible?

[ Edited ]

@JasonTitcomb  Do you mean for just a visual comparison?

BTW: I didn't mean to post twice above. The first one didn't show up for quite a while for some reason so I did the second one.

Bruce Shand
ST9 MP8 - Insight - Win10 - K4200

Re: Displaying constraints intuitively in Synchronous mode: Possible?

I have the same problems as most in this thread. But the way I look at it is in terms of assembly relations.


In Sync, it checks and sets all the relations at once. Yes they can be de-coupled, but there is no way to know easily what relations are being used. You have to navigage through the plane and concentric realtions of sync.


I wish there was a way to treat Sync relations like Ordered relations One by one, and have a way to list each relation again one by one.


I stay away from Sync for this reason and because I can't directly control sheet metal flat pattern sizes in Sync.


If thoese two thing were changed in the software, I may consider Sync, expecially if changing gages of Sync sheet metal gage was predictable like ordered. If you change the gage of an ordered sheet metal part, it typically does not turn out as intended.