what does this mean: " sketch is fully constrained"

[cekuhnen]

I followed the video also activated preview sketch in preferences but cannot replicate the same visual color changes for sketches.

How is this supposed to work? The video does not really explain the ideas behind it very clearly. It mentions great feedback but what feedback?

[HughesTooling]

It's definitely worth having. You can get some nasty surprises when a sketch is not fully constrained and part of the sketch uses reference geometry.

Mark.

[Anonymous]

Very true.  But because of the ease of sketch re-editing, my general approach is to just get "constraint crazy" when a problem arises.

Jesse

[Anonymous]

LOL, Daniel you haven't been watching too many sci-fi cyborg movies? 

[Anonymous]

Daniel, I'd be interested in seeing sometime a screenshot or something of when a problem comes up for you of the sketching going mad.

Jesse

[cekuhnen]

I guess thats the downsides of sketches like in Fusion because they are interactive you can get really funny things.

So you need to be aware of certain problems and constrain it right.

The ability to move a line and let others follow or os is really a nice advantage over drawing in Alias or Rhino where it is static.

[kevin]

...

[kellings]

When I moved to Inventor from AutoCAD, sketching and constraining was one of the harder concepts for me to grasp. I've taught a lot of Inventor classes and I see those students go through the same issues to start out with.

In programs like AutoCAD you draw a line a specific length and then the dimension you place shows you how long that line is. In a parametric sketcher, you draw a line of some length and then the dimension tells the line how long it should be. In programs like AutoCAD the geometry is fixed until you use a command to modify that geometry such as move, trim, extend, etc. In Fusion the geometry wants to move until you add dimensions or constraints that control how your sketch will react as you make changes. Constraining and deminsioning simply contols your design intent and ensures the sketch reacts in a predictable way.

So while you technically don't need to constrain and control your sketches, once you learn how, it becomes second nature and very powerful.

[Anonymous]

Yeah, I guess there is also lack of terminology clarity of the difference between constraints, and dimensions.  I'm very careful that the proper constraints exist so that there is no funny business and modifies well from parametric changes.  However for many things there will be a few critical dimensions, but the rest can be dragged to what "looks good," especially for the time being.  Also I've normally found no need to constrain sketch geometry to the origin or an anchored point.  I find this "laid back" approach nice, especially for someone developing all their awarenesses of what to keep in mind while modeling (which is a lot to begin with), and of course during the initial phases of developing a design.  During such times, these fully constrained/dimensioned indicators seem to potentially become an actual significant distraction that as said doesn't really need to be there oftentimes. 

Jesse 

[kb9ydn]

---

@Anonymous wrote:

Yeah, I guess there is also lack of terminology clarity of the difference between constraints, and dimensions.  I'm very careful that the proper constraints exist so that there is no funny business and modifies well from parametric changes.  However for many things there will be a few critical dimensions, but the rest can be dragged to what "looks good," especially for the time being.  Also I've normally found no need to constrain sketch geometry to the origin or an anchored point.  I find this "laid back" approach nice, especially for someone developing all their awarenesses of what to keep in mind while modeling (which is a lot to begin with), and of course during the initial phases of developing a design.  During such times, these fully constrained/dimensioned indicators seem to potentially become an actual significant distraction that as said doesn't really need to be there oftentimes. 

Jesse 

---

I think anchoring sketches to the origin becomes more important if you intend to use the built in reference planes (or origin) for mating to other components.  If you only ever use the part geometry itself for mating to other components then the position of the part inside its component is not important.  I used to not worry so much about it until I realized that I could save myself some work later on by making sure to orient my part within its component *from the beginning*, thereby allowing use of the built in reference planes.  Once I started doing this I found that I needed to create special reference geometry less often because the built in planes were usually sufficient.

When you're first starting out with CAD I suppose it may seem like it slows things down, but now that I've become more proficient I don't even think about it.  When starting a new sketch I just automatically start at the sketch origin, or some other existing geometry point, and add constraints and dimensions as I go.  Even for conceptual stuff I tend to fully define everything simply out of habit (for sketches anyway, not so much for component mates).  So to me, the sketch constraint indicators are exactly the opposite of a distraction, they are a necessity.

I think this may actually be related to a more general design approach (I have) of needing to have a clear idea of what I want to end up with before I start any modelling.  I tend to think a lot about what I want to do before I start doing it.  This way I won't end up wasting time have to redo something that didn't turn out right.  Of course this doesn't always work and some amount of iteration is inevitable, but I like to keep it to a minimum.  Other people I know are exactly the opposite and will immediately start scribbling like mad, hammering away at it until they get what they want.  This approach feels too haphazard to me, but I guess we all have out own ways of doing things.

C|

[daniel_lyall]

if you know what can go mad and how to stop it work with it, any way you do it will work, so far the constrant`s seem to be good fixed I have not had a constrained drawing go funny with no grounding so far 

[Anonymous]

That's true, I've never really turned on visibility and used a component's coordinate system references (CSR) much (the origin, and 3 axises and planes).  I suppose when developing my workflows, there is always a student in the back of my mind.  Learning extremely powerful yet consequently "involved" new things can be quite intimidating to many I've found, such as programming, math/science, electronics, and of course CAD and CAM.  But it doesn't really need to be so intimidating, if a person can just start getting into it.  A key to that for an educational system is always focusing leveraging all possible simplification.  So for example, CSR could be introduced right away, but it's clearly not necessary, while it is necessary to define sketches, joints, etc. to existing geometry (faces, edges, etc) in order that interfaces are maintained when said reference geometry is changed via driving sketches.

This notion of learning simplification above all else (which BTW Fusion 360 seems perfect for) also applies to the sketching issues we are talking about.  Although as I said before now that it appears the overconstraint bugs associated with coincident with the origin are fixed, I may try that again.  But again the question arises, is that truly an additional detail worth  introducing into the early stages of an empowering learning system (empowering being that allows many people to get into what otherwise they would not have).  It's like designing a satellite or something, every little detail must be scrutinized to achieve a feasible system in the end (meet demanding payload limits, reliability, cost etc).  As a person progresses in their familiarity with CAD, in a "progressive" educational system I'm talking about, then further advanced details are introduced in due course.  But the initial stages need to be very streamlined.  It's amazing what a delicate time that is for many, and even seemingly small hangups or detail overload can end up being catastrophic (i.e. termination of progression). 

But considering this stuff is really important to achieving a mass popular rise of empowerment via these tools and knowledge 🙂

Jesse

[maritza.ga]

Thank you all for this incredible feedback. This functionality is something we have been working on to help improve the experience of sketching. As @Anonymous stated, this sort of feedback is exactly what we are looking for by releasing a PREVIEW of the functionality. As we continue to work on the functionality we will keep all of your feedback in mind. The issues that you report to us help us kink out all the bugs to create a more robust solver.

Along side this functionality we have been working on the overall solver of sketching to fix the over constrained issues we have had. As some have noticed, turning on this functionality brings about new solve issues. We invite you to play around and experiment wtih this new functionality and continue to offer us feedback  as we do the last bit of tidying up to make this full release worthy. 

Thank you,

Maritza  

Fusion 360 UX Designer

[daniel_lyall]

you ask for it I will see if I cant kill it just to find bugs 

[daniel_lyall]

@Anonymous Doctor Who 

[Anonymous]

Thanks Maritza for all the work you guys do!  I have definitely noticed the overconstraint bugs I've come across before are now gone. 

Regarding the constrained color indication, I'm trying to decide if I should incorporate it into an interactive learning program I'm now going to undertake in producing for Fusion 360.  One deciding factor is if you expect that at some point it will be a mandatory feature that cannot be deactivated?  It's important to me to aim at producing content that will be as close to relatively near future behavior as possible.

Thanks,

Jesse 

[Anonymous]

That explains it 😉

[Anonymous]

Onshape has a great constraint solver and feedback. Solidworks is pretty good, too. I don't know about the fiddly bits going on with code but it seems like Fusion is pretty out there compared to other programs in how it functions under the hood, so it may not be useful to compare these tools. Looking forward to Fusion's sketch tools becoming more robust in the future! As a parametric modeller, being able to quickly build constrained sketches is really important to me! 

[kellings]

I believe most of the solid modelers license the same constraint solver, D-Cubed. If I remember correctly, Autodesk is building their own. Might be the reason we are seeing some rough edges. I could be completely wrong though. 

The tools that Autodesk is giving us in Fusion help with not worrying so much if your parts are drawn around the origin plane or point. I think that is where I am having some of my difficulties. It's been so beaten into my head that step one is to construct your sketch relative to the origin, now that isn't the case as much. I have to unlearn a bit. I wouldn't doubt that my Inventor experience actually hinders me a bit in Fusion. 

[cekuhnen]

Now if the sketch module could provide CV curves and blend curves it would be a great engine.

After 2 years testing 3d splines and handle dimensions I still think they are inferior to work with compared to

a parametric blend curve were you just set the weights for each side.

This specifically would be a perfect match for 3d sketches where dimensioning in 3D space doesn't work currently anyway.

This would combine a great workflow from systems like Alias (surface modeler) and a typical solid modeler Fusion in one package.

[kellings]

And that is their challenge. I really don't understand what you just said (yeah, I get the gist of it, but I'm no expert like you are). I don't envy them making a tool that is simple enough for everyone yet also has the funtionality that power users need without adding the complexity.