52 Replies Latest reply on Oct 18, 2017 3:55 PM by John Stoltzfus

    Fully Defined Sketch

    Maha Nadarasa

      Sketch is a fully defined one but one of the dimension (I do not how to call it) is still blue color. What is the reason?

       

      1.png

        • Re: Fully Defined Sketch
          Glenn Schroeder

          Dimension colors don't have anything to do with whether or not a sketch is fully defined.  That only applies to actual sketch geometry (lines, endpoints, etc.).

          • Re: Fully Defined Sketch
            Bjorn Hulman

            Hi Maha,

            I think this is an anomaly with splines. I tried to re-create the issue, and initially, I dimensioned one end and the dim went black, I dimed the other end and they both went blue. I deleted the dims and re-applied them, and they both went black. I deleted the spline and dimed them and they went black.

             

            I've noticed this before, and to check the sketch is defined I just try to drag around a few points / leaders to see if they're stable.

            • Re: Fully Defined Sketch
              Christian Chu

              it's spline length and if you redim, it turns black once the sketch is fully constrained

                • Re: Fully Defined Sketch
                  Maha Nadarasa

                  Christian Chu wrote:

                   

                  it's spline length and if you redim, it turns black once the sketch is fully constrained

                   

                  Two various length for one spline?

                    • Re: Fully Defined Sketch
                      Bjorn Hulman

                      note Christian has used a style spline. Though that shouldn't make a great deal of difference.

                      • Re: Fully Defined Sketch
                        Christian Chu

                        Maha,

                        Your sketch is not fully constrained. You can edit the dim 75 and change its value - what I mean is your sketch is not fully constrained until you add the spline length

                        Edit: you can also remove the dim 75 and drag the handle up/down . It'll be locked soon you add the spline lenght (fully constrained or fully defined sketch as you call it)

                          • Re: Fully Defined Sketch
                            Matt Lombard

                            No, his sketch is fully defined as shown because the vertical relation applies to the arrow. Look at the first image in the thread, it clearly says fully defined, and all the entities are black. If you add a spline length dimension it goes overdefined. Dimension colors do not determine under/fully defined in SW. Style splines do not have tangency arrows. With a style spline you dimension the polygon directly. A regular 2 point spline with no through points acts exactly like a style spline, except it displays tangency weighting arrows, and you can add through points to it. Style splines just let you add control polygon points.

                              • Re: Fully Defined Sketch
                                John Stoltzfus

                                Matt Lombard  wrote:

                                Dimension colors do not determine under/fully defined in SW.

                                 

                                I have to respectfully disagree -

                                 

                                  • Re: Fully Defined Sketch
                                    Matt Lombard

                                    Yes, a driven dimension is usually gray. That doesn't have anything to do with fully or underdefined. The sketch element color reflects fully/under defined, not the dimension.

                                     

                                    Try this. Draw a circle in space, not at the origin - the circle is blue.

                                    Add a diameter dimension - the dimension is black. the circle is blue.

                                    Drag the circle to the origin - both dimension and circle are black.

                                    Extrude it and double click the solid - the diameter dimension is black, and the depth dimension is blue.

                                      • Re: Fully Defined Sketch
                                        John Stoltzfus

                                        Looking a Maha sketch above and comparing it to the one I have shown could be the same....  I sure didn't get myself clear on that reply

                                         

                                        The depth dimension has nothing to do with the sketch btw - a 2D sketch has no depth...

                                          • Re: Fully Defined Sketch
                                            Matt Lombard

                                            The depth dimension has nothing to do with the sketch btw - a 2D sketch has no depth...

                                            Yeah, I totally agree, just showing the blue color denotes something else not related to the sketch state.

                                              • Re: Fully Defined Sketch
                                                John Stoltzfus

                                                The OP called out the dimension color, that's why I took it down that road...  While sketch dimension color doesn't tell us the status of the sketch definition.

                                                  • Re: Fully Defined Sketch
                                                    Matt Lombard

                                                    Yeah, that dimension might have been a graphics glitch or something. Not sure.

                                                    Did you change your driven dimensions to blue, or are you using a different color scheme? Default is gray.

                                                      • Re: Fully Defined Sketch
                                                        John Stoltzfus

                                                        I changed most of my color schemes... -

                                                          • Re: Fully Defined Sketch
                                                            Matt Peneguy

                                                            John Stoltzfus,

                                                            Just to expand on your reply for anyone reading this thread, depending on your workflow, changing the standard colors can really help.  I'll give an example of how this helps my workflow. SWX default color for dangling dimensions and annotations in drawings is a drab green (IIRC), which doesn't stand out too well from other annotations.  I really like to see if something is not attached and changed dangling to red and look how much they stand out:

                                                            If you see a color for something that doesn't work for you...change it!

                                                              • Re: Fully Defined Sketch
                                                                Dan Pihlaja

                                                                I changed the color of undefined sketch entities to be a bright, galling, in-your-face, red.

                                                                 

                                                                That way, those little lines that sometimes come up can be easily seen.

                                                                  • Re: Fully Defined Sketch
                                                                    Matt Lombard

                                                                    Hmmm.

                                                                     

                                                                    This might sound crazy coming from me, but can someone describe to me exactly why you are so afraid of underdefined sketches? I will inevitably ask you to demonstrate whatever you come back with. I'm becoming skeptical about most of the superstitions about underdefined sketches. Please convince me I'm wrong.

                                                                      • Re: Fully Defined Sketch
                                                                        Christian Chu

                                                                        Here is one example:

                                                                        For my industrial design, I use spline a lot in my sketches. the spline is "relaxed" to begin with so I can easily shape the design to look nice but fit into the machine. Once it's done, I'd go back to "nail" all the spline since there is a chance I or other engineers might edit the sketch and drag the handle which would ruin  the design

                                                                        • Re: Fully Defined Sketch
                                                                          Glenn Schroeder

                                                                          Years ago when I took the Essentials class at my local VAR the instructor related to us that he knew of a situation where a guy didn't take the time to fully define a sketch.  Somehow something got inadvertently moved and no one caught it until the part was in production.  It cost the company several hundred thousand dollars and cost the CAD guy his job.  I don't want to be that guy.

                                                                          • Re: Fully Defined Sketch
                                                                            Matt Peneguy

                                                                            I'm sure Dan is going to answer you, but I have a question about this line of thinking.  Devils advocate, here...If the rule is broken to allow underdefined sketches, where does that line of reasoning stop?  I'm not being facetious, I'm being serious.  You know what you are doing, and probably have as good a handle on this as anyone, but most people aren't as versed in what is acceptable and will work robustly.  I apparently am not as adept at making that determination and got burned by using underdefined sketches a little while back.  I'll give you that example.  I used an underdefined spline to define the profile for the cross section of the concrete below because the structural guys have it as a parabolic.  Well something got moved...and my weights were different than the structural guys.  Come to find out the spline had shifted.  I don't know how.  But, it took me a while to figure out.  I have since replaced the spline with fully defined line segments.

                                                                            So, I'm sure if you are careful, you can use underdefined sketches.  But how do you determine what is acceptable and how do you set those rules?

                                                                              • Re: Fully Defined Sketch
                                                                                Matt Lombard

                                                                                Yeah, see, that's the problem. I'm not saying there's a problem with the settings or the best practice rules or even that there's anything wrong with the superstition. I'm just saying that sketch based features are dangerous. Partially defined sketches are dangerous. Fully UNdefined sketches are the only truly safe way to make sure nothing changes automatically. Well, that or an IGES file.

                                                                                 

                                                                                I can show you ways to move stuff you think is fully defined without editing a dimension.

                                                                                 

                                                                                I have yet to see a fully undefined sketch move at all unless it is directly tampered with.

                                                                                 

                                                                                I lost $5000 on a job once because of an unrelaxed spline that sprung from one shape to another with a rebuild. Someone else opened my file, hit rebuild, and saved out an STL without checking the part. It wouldn't have mattered one bit if it was fully defined or not.

                                                                                 

                                                                                Data that thinks for itself is inherently dangerous. I've spent the last 4 years living in a world where data doesn't think for itself. There are fewer "spooky action at a distance" sort of things that happen.

                                                                                 

                                                                                I think the security you think you have with fully defined sketches is 100% illusion. It's just as vulnerable to deliberate tampering, mistakes, quirks in the software, etc. as anything else. The more intelligence you build in, the more vulnerable your data is.

                                                                                  • Re: Fully Defined Sketch
                                                                                    Matt Peneguy

                                                                                    I am confused as to how you would make a fully undefined sketch model in SWX.  Can you show us what you mean?  I am always open to new or better ways of doing things.

                                                                                      • Re: Fully Defined Sketch
                                                                                        Matt Lombard

                                                                                        Well, you could just delete all the sketch relations.

                                                                                        I'm not really suggesting that you do that, by the way. I'm just saying the sense of security in a fully defined sketch is mostly an illusion. If it makes you feel better to do that, go ahead.

                                                                                        I'm kind of working through an idea in my own head for a way to improve on this whole sketch-feature-parent/child-history fiasco. I mean, it's all these dependencies that cause cascading feature failures when you make changes. And as often as not, it's your "design intent" that is getting changed, isn't it?

                                                                                        This might also sound obtuse, but intelligence in the editing tools to me is safer than intelligence in the data itself. Does that make sense?

                                                                                         

                                                                                        Matt,

                                                                                        I'm totally confused here, like Matt

                                                                                        You mean "fully defined sketch" is a wrong approach ???

                                                                                        Ummm, yeah, sort of. I mean, I don't think it's something you can do differently within SW, I just think conceptually, there has to be a better way. We all, and I include myself in this, have spent decades immersed in this way of thinking, but it causes so many errors.

                                                                                          • Re: Fully Defined Sketch
                                                                                            John Stoltzfus

                                                                                            Matt Lombard wrote;

                                                                                            I just think conceptually, there has to be a better way. We all, and I include myself in this, have spent decades immersed in this way of thinking, but it causes so many errors.

                                                                                            I am very open to new ways and trying new trouble free concepts.  The errors you talk about are mostly user driven, you more then likely understand SW a lot more the all of us, but I will tell you most of my assemblies are error free from the beginning and I am able to make parametric changes very easily.  To do that you need a fairly tight system or process.

                                                                                              • Re: Fully Defined Sketch
                                                                                                Matt Lombard

                                                                                                John Stoltzfus wrote:

                                                                                                I am very open to new ways and trying new trouble free concepts. The errors you talk about are mostly user driven, you more then likely understand SW a lot more the all of us, but I will tell you most of my assemblies are error free from the beginning and I am able to make parametric changes very easily. To do that you need a fairly tight system or process.

                                                                                                 

                                                                                                 

                                                                                                Yeah, I agree. It probably also depends on what kind of stuff you make.

                                                                                                 

                                                                                                Sorry to get everyone riled up. Just thinking about some of that stuff today.

                                                                                                  • Re: Fully Defined Sketch
                                                                                                    Dan Pihlaja

                                                                                                    Matt wrote:

                                                                                                     

                                                                                                    John Stoltzfus wrote:

                                                                                                    I am very open to new ways and trying new trouble free concepts. The errors you talk about are mostly user driven, you more then likely understand SW a lot more the all of us, but I will tell you most of my assemblies are error free from the beginning and I am able to make parametric changes very easily. To do that you need a fairly tight system or process.

                                                                                                     

                                                                                                     

                                                                                                    Yeah, I agree. It probably also depends on what kind of stuff you make.

                                                                                                     

                                                                                                    Sorry to get everyone riled up. Just thinking about some of that stuff today.

                                                                                                     

                                                                                                    Its all good Matt.   And I will agree that what you say has its place (regarding undefined sketches specifically).  Like if you are making one-offs and never editing said things once you launch them.  And I also understand about the "more technology = more catastrophic screw ups"

                                                                                                     

                                                                                                    However, let me give you an example:

                                                                                                     

                                                                                                    In a company that I once worked for, there were 2 designers that worked in the division that I was in (there were other Solidworks users, but they didn't do as much design work).

                                                                                                    Designer 1 does as little as possible to fire the design out the door.  His motto is that, if it needs changes, they will do them on the shop floor because it is impossible to get things exact in the real world and trying to add tolerances and things just gums up the business.  He leaves his sketches as undefined and never parametrically links anything.  In fact, most of the time, his assemblies are just thrown together without fully defining his components.  Yes, he rarely has update issues and the time it took for him to fire that assembly design downstream to the programmers was very fast.

                                                                                                     

                                                                                                    However, when it came time for him to make a change to the base plate of the fixture (he had to move a row of mounting holes to a new location because of an interference with a portion of the machine).

                                                                                                    This changed the location of 3 components downstream and of course changed the location of all the mounting holes of all 3 components.

                                                                                                    He had to spend about 2 days getting everything back in order in his assembly after modifying all the parts that were involved (I kept hearing him yell that his sketches kept blowing up and he had to redo a bunch of stuff), and then, when all was said and done, he had forgotten to move one hole and a part was scrapped because of it.    This part was a casting that cost us $25,000.00 just to purchase the casting.

                                                                                                     

                                                                                                    Designer 2 had a very similar situation, however, in his design, he spent extra time (about a day's work) making sure that his design intent was shown in all the sketches and even linked all the mounting holes together with a skeleton sketch buried at the top if his main assembly.

                                                                                                    When it came time to make the change to the base plate, he changed 1 dimension in 1 sketch, then ran an update cycle.  This updated all locations of all mounting holes for all components and then he just had to update the print.

                                                                                                    Took all of 20 minutes, most of which was updating the prints and releasing the new revisions.

                                                                                                     

                                                                                                    This is what I am talking about with ease of modification and the importance of fully defining things.

                                                                                                      • Re: Fully Defined Sketch
                                                                                                        John Stoltzfus

                                                                                                        Follow Designer 2 People, follow that guy, it sounds easy and it is.  Just to add onto Dan Pihlaja awesome reply - If you can figure out the design intent and name the sketches and some dimensions right up front, then if you have any changes go to the equation manager and filter the dimensions, find the one needing changed and type in the new values hit ok and watch it move and everything moves like ballet

                                                                                                  • Re: Fully Defined Sketch
                                                                                                    Matt Peneguy

                                                                                                    Matt Lombard wrote:

                                                                                                     

                                                                                                    I'm kind of working through an idea in my own head for a way to improve on this whole sketch-feature-parent/child-history fiasco. I mean, it's all these dependencies that cause cascading feature failures when you make changes. And as often as not, it's your "design intent" that is getting changed, isn't it?

                                                                                                    This might also sound obtuse, but intelligence in the editing tools to me is safer than intelligence in the data itself. Does that make sense?

                                                                                                     

                                                                                                    I am in complete agreement that this parent/child situation can be a lot of trouble, and you have to be very careful in how you plan your design because of it.  However, it is what we have to work with or around with SWX.

                                                                                                    To address your second question, I don't know enough about "intelligence in the editing tools" to be able to intelligently respond to your question.  I'm sure you are onto something.  I just don't know what it looks like.

                                                                                                • Re: Fully Defined Sketch
                                                                                                  Christian Chu

                                                                                                  Matt,

                                                                                                  I'm totally confused here, like Matt

                                                                                                  You mean "fully defined sketch" is a wrong approach ???

                                                                                              • Re: Fully Defined Sketch
                                                                                                Dan Pihlaja

                                                                                                Matt Lombard wrote:

                                                                                                 

                                                                                                Hmmm.

                                                                                                 

                                                                                                This might sound crazy coming from me, but can someone describe to me exactly why you are so afraid of underdefined sketches? I will inevitably ask you to demonstrate whatever you come back with. I'm becoming skeptical about most of the superstitions about underdefined sketches. Please convince me I'm wrong.

                                                                                                A few things here:

                                                                                                 

                                                                                                1) A defined sketch shows the design intent of the designer to anyone else who needs to modify that particular sketch.

                                                                                                     Case in point: https://forum.solidworks.com/message/483562#comment-483562  (Walter Fetch's example near the bottom)\

                                                                                                 

                                                                                                2) An under-defined sketch is completely unpredictable when it comes to editing said sketch.   Here is an article detailing this:

                                                                                                     Tips for New SOLIDWORKS Users Part 3: Fully Define, Every Time

                                                                                                Specifically: "That’s the problem with underdefined sketches – we don’t know what’s going to happen when we change a dimension because we haven’t defined all the rules that govern that sketch.  This will lead to rebuild errors which can often be confusing and time-consuming to resolve."

                                                                                                and here:

                                                                                                Sketching: The basis of Solidworks - 3D Engineer

                                                                                                "Full defined sketches: Making sure a sketch is fully defined is simply good practice. Under defined sketches cause major problems when changes must be made, arcs over extend, lines cross, dimensions loose defining vertices, and features fail. It is much easier to go back and remove definition that it is to painstakingly correct each error caused by an under defined sketch"

                                                                                                 

                                                                                                 

                                                                                                3) Even if you partially defined a sketch, leaving it as under defined will still show the little ( - ) symbol.   Now, when you have to pause on this project and come back to it (or turn it over to another designer), how do you know you are done with that portion of the sketch?  Making sure everything is fully defined is generally a big clue that you have completed that step.

                                                                                              • Re: Fully Defined Sketch
                                                                                                Maha Nadarasa

                                                                                                What color have you given for over defined sketch?

                                                                                          • Re: Fully Defined Sketch
                                                                                            John Stoltzfus

                                                                                            Matt Lombard wrote:

                                                                                            Did you change your driven dimensions to blue, or are you using a different color scheme? Default is gray.

                                                                                             

                                                                                            I also color my macro buttons 

                                                                                             

                                                                                • Re: Fully Defined Sketch
                                                                                  Christian Chu

                                                                                  I believe the user needs to understand when the sketch is "fully constrained" than depend much on the software

                                                                                  To me, the below sketch is "fully constrained" - dragging the "blue" line around won't change the profile of the sketch. Question is: how rarely we use radius dim to define the circle?

                                                                                  Back to OP, I'd rather dim the spline length than the handles

                                                                                   

                                                                                   

                                                                                    • Re: Fully Defined Sketch
                                                                                      Glenn Schroeder

                                                                                      Christian Chu wrote:

                                                                                       

                                                                                      I believe the user needs to understand when the sketch is "fully constrained" than depend much on the software

                                                                                      To me, the below sketch is "fully constrained" - dragging the "blue" line around won't change the profile of the sketch. Question is: how rarely we use radius dim to define the circle?

                                                                                      Back to OP, I'd rather dim the spline length than the handles

                                                                                       

                                                                                       

                                                                                       

                                                                                      ..until you reference other geometry off that construction line.  In this particular case I agree that it's position isn't important, but in other situations it can be very important.

                                                                                      • Re: Fully Defined Sketch
                                                                                        Matt Lombard

                                                                                        Yes, of course, construction geometry adds value, but shouldn't distract from other things.

                                                                                         

                                                                                        By the way, there's a time when the sketch will be all black, and the bar at the bottom will say "Fully Defined", but you can still drag points. (Endpoints of converted entities show as black, but can still be dragged unless you have constrained them separately)

                                                                                         

                                                                                        Plus, using your settings, it's possible for a sketch to look fully defined when it's not. If you don't show sketch points, the endpoints of a line can be blue, even if the line itself is black. This can happen when a horizontal line from the origin does not have a length dimension. Try it.

                                                                                         

                                                                                         

                                                                                        By the way, if you don't dimension the handles, you can't control the direction or weight of the tangency. Not that I'm an advocate of fully dimensioning splines. I'm not.

                                                                                    • Re: Fully Defined Sketch
                                                                                      Maha Nadarasa

                                                                                      I did the way you told as a result with value 75 it change it color from blue into black. I do not know what happened.

                                                                                       

                                                                                      1.png

                                                                                  • Re: Fully Defined Sketch
                                                                                    Matt Lombard

                                                                                    The 75 and 65 dimensions are the weighting of the tangency control for the spline.

                                                                                    Trying to fully define spline sketches is a bit of a waste of time, like herding cats. Make sure the spline is "relaxed" (click on it, and Relax Spline is in the PropertyManager).

                                                                                      • Re: Fully Defined Sketch
                                                                                        Christian Chu
                                                                                        Trying to fully define spline sketches is a bit of a waste of time, like herding cats. Make sure the spline is "relaxed" (click on it, and Relax Spline is in the PropertyManager).

                                                                                        Matt,

                                                                                        it's true for "spline" while many want to control the length of the "style spline" for their design purposes

                                                                                        • Re: Fully Defined Sketch
                                                                                          Maha Nadarasa

                                                                                          Matt Lombard wrote:

                                                                                           

                                                                                          The 75 and 65 dimensions are the weighting of the tangency control for the spline.

                                                                                           

                                                                                          What is meant by "tangency control"? Could you explain it?

                                                                                          • Re: Fully Defined Sketch
                                                                                            Maha Nadarasa

                                                                                            What do the different values (65, 75) mean?

                                                                                              • Re: Fully Defined Sketch
                                                                                                Matt Lombard

                                                                                                Maha Nadarasa wrote:

                                                                                                 

                                                                                                What do the different values (65, 75) mean?

                                                                                                I'm not sure if those values have any units, they are just "weighting" numbers for the tangency. It works as if you could change the stiffness of the spline where ever you have one of these arrows. A long arrow means it's very stiff, so the spline is very straight in that area. A short area means its not stiff on that end, so it can curve tightly there.

                                                                                                  • Re: Fully Defined Sketch
                                                                                                    Dan Pihlaja

                                                                                                    Matt wrote:

                                                                                                     

                                                                                                    Maha Nadarasa wrote:

                                                                                                     

                                                                                                    What do the different values (65, 75) mean?

                                                                                                    I'm not sure if those values have any units, they are just "weighting" numbers for the tangency. It works as if you could change the stiffness of the spline where ever you have one of these arrows. A long arrow means it's very stiff, so the spline is very straight in that area. A short area means its not stiff on that end, so it can curve tightly there.

                                                                                                     

                                                                                                    I believe that they are percentages.  Where 0 would equal perpendicular and 100 would equal coincident/parallel.

                                                                                                      • Re: Fully Defined Sketch
                                                                                                        Matt Lombard

                                                                                                        Dan Pihlaja wrote:

                                                                                                         

                                                                                                        I believe that they are percentages. Where 0 would equal perpendicular and 100 would equal coincident/parallel.

                                                                                                        I was able to take one to 2000. Tried to go to 50000, and it said "Please enter a number greater than or equal to 0.00000394 and less than or equal to 39370.07874016. That's just the normal range of numbers SW can handle, isn't it? So I think it's just a multiplier number.