Error in tutorial: "Coincident vertices may need to be welded together..."

kdeuler
Advocate

Error in tutorial: "Coincident vertices may need to be welded together..."

kdeuler
Advocate
Advocate

I'm get this error:

 

"Error: Conversion error for: Body2
Coincident vertices may need to be welded together. Look for vertices where edges are converging together."

 

 

...when I attempt to save the spoon form created at the end of Mr. Sharma's lecture "Section 1, lecture 4 is entitled "Exploration and ideation using Fusion 360: Sculpting - spoon"  in this udemy class:

 

https://www.udemy.com/design-for-innovation-using-fusion-360-water/learn/v4/content

 

After i do the thickening at the end of the lesson, and then try to close the form, the error occurs. The error also occurs if I attempt to save the form BEFORE doing the thickening.

 

If you look closely at bottom of the spoon bowl near the end of Mr. Sharma's lesson, you can see that he has the same symptom I have after the thickening (but before leaving the Form mode): There is a small hole there. The error doesn't appear in the lesson, though, because the lesson concludes without him exiting the Form mode.

 

Two questions:

 

  1. Does anyone agree that this is probably a Fusion 360 Bug?
  2. Is there any way to correct "cooincident vertices" problems, whether or not their creation was the result of a bug?

 

Thanks!

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TrippyLighting
Consultant
Consultant

Without having access to your design file only general advice can be provided. 

If you can export your design as a .f3d and attach it too you next post we'll have a look at it.

 

While in the sculpt environment, have you tried "Utilities-> repair body" ?


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kdeuler
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TL-  OK I've done two things

 

1) Created this archive file as you suggested:

 

    http://a360.co/29Rcu9q

 

2) Made this screen cast, whose description reviews the problem, and adds my just-now discovery as to where the vertex issue originates:

 

    http://autode.sk/2apa9RK

 

 

What I've done is a few basic compress/stretch actions on a sphere section. I'd be surprised if this vertex issue isn't a bug, but of course I'll wait for your verdict!

 

Thanks!

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masa.minohara
Alumni
Alumni

Hi @kdeuler,

 

Thank you for posting this! I just noticed that the body in your design is self-intersecting and this is causing another issue. 

 

self intersecting.JPG 

 

Regarding the vertex issue, if you create a sphere in Sculpt environment, the vertex of a sphere is not welded by default and this can be fixed by using Repair Body command.

 

repair body.JPG

 

I made a screencast video that shows how to fix those issues. Please let me know if you have any questions!

 

Masanobu Minohara

Product Support Specialist



Fusion 360 Webinars | Tips and Best Practices | Troubleshooting
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kdeuler
Advocate
Advocate

@masa.minohara , thanks  for your comments and video. The video went rather quickly for me, and I didn't have the success you had in making the repairs, but that's OK (for now).

 

It's not clear from your comments that this vertex trouble is considered a bug or "as designed". My view is that , at the very least, F360 should throw a warning when a sphere-based drawing (perhaps other form types too) enters into a state where it cannot be "saved" via Exit Form. As it is now, one can continue along with several hours of designing a form, not knowing that some sphere stretching/pulling made much earlier prevent the exit from forms mode. Users could loose a lot of time if they find that they can't fix the vertex error satisfactorily with the Fix Form utility. For example, with your first fix of the spoon, I see how most of the lines in the spoon disappeared after you did the Fix Form. This might not be desired. (Note: I just played with a sphere, and I found that its very easy to make a non-Exit-Form-able adjustment, especially when working around the poles.)

 

 

The best scenario of course would be for the issues not to appear at all, so that vertices, etc., are moved to non-self-intersecting places real-time during the stretch action. But this might be difficult to do programmatically.

 

Please let me know the status of this thread. Does it live as a bug? Should it be placed in the IdeaStation?

 

 

Thanks!

 

cc @TrippyLighting

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masa.minohara
Alumni
Alumni

Hi @kdeuler,

 

Thank you for your response!

 

As far as I can tell, it's behaving as designed and giving errors because something should be fixed. However, I totally agree with you on the idea about giving a warning as soon as something goes wrong so that a user can fix it on the spot, and I believe that will be a great enhancement request.

Masanobu Minohara

Product Support Specialist



Fusion 360 Webinars | Tips and Best Practices | Troubleshooting
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TrippyLighting
Consultant
Consultant

This is not an error and Fusion 360 can not and should not fix this automatically. A waring about  self intersection is be fine but the T-Spline should be converted  nonetheless.

 

However, Fusion 360's unwillingness to simply convert the T-Spline despite the self intersection is limiting more experienced users from accomplishing their work and requires convoluted workarounds as can very easily be seen in this thread.


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kdeuler
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@masa.minohara@TrippyLighting

 

Thanks again for your comments above.

 

I had subsequent coincident vertices issues with Mr. Sharma's next two tutorials, namely the rubber ducky, shown here after I did a Fix Body, which blew away the lateral vertices:

 

http://a360.co/29PjKEt

 

And just now with the water bottle lesson:

 

http://a360.co/2afo12c

 

Perhaps one of you could examine the water bottle item and see if you can have success repairing the vertices issues in the cap. I'm getting these errors after taking care to follow Mr. Sharma's video as closely as possible.

 

FYI, I recently filed a feature request to have the vertices issue warning occur at the time of coincident-creation, rather than at the later Finish Form button.

 

Thanks!

 

 

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TrippyLighting
Consultant
Consultant

Looking at your file, the way the cap is closed with polygons is questionable. While the outside of the top of the cap does not exhibit triangles the inside certainly does.

In T-Spline modeling try to avoid triangles at all cost. Triangles are evil 😉

 

If you apply the method of how to dome a cylinder in the second tutorial just posted in this thread your T-Spline will convert just fine.

Actually, you should re-do the bottom of the bottle that way as well.

 

 

 


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kdeuler
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OK thanks TL. I'll try this.

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