Form is unaffected by extrude

Form is unaffected by extrude

Oli_Young
Enthusiast Enthusiast
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Message 1 of 9

Form is unaffected by extrude

Oli_Young
Enthusiast
Enthusiast

Hi, I have got a form here, that seems to avoid being cut by an extrude. Can you tell me what is wrong?

 

https://a360.co/2Kejjoi

 

Thanks

 

image.png

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Message 2 of 9

TrippyLighting
Consultant
Consultant

There are a number of warnings in your design that you might want to address before continuing with it.

 

Screen Shot 2018-06-21 at 6.30.46 AM.png


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Message 3 of 9

TrippyLighting
Consultant
Consultant

Aside from that, however, your design has fallen victim to one of the many bugs when working with T-Splines.

 

@jeff_strater this is another case where we have an orphaned T-Spline that is clearly visible in the viewport but after leaving the T-Spline form does not show up as a body.


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Message 4 of 9

Oli_Young
Enthusiast
Enthusiast

#OrphanedTspline - I see it's an actual thing now! 

 

Thanks for taking the time to look at the example. It's a student's work, and I am trying to resolve the issues.

 

I have edited the form (1), and hidden the two bodies in the browser (2), but another (orphan) t-spline form is visible and unselectable/uneditable (3). Is this just a bug which we just got to put up with? 

 

image.png

 

 

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Message 5 of 9

TrippyLighting
Consultant
Consultant

This bug seems ot only occur when 2 T-Spline meshes are created in a single form feature (the on in the timeline) that would usually convert into 2 separate solid bodies. That's also the reason why there are 2 T-Spline bodies in the timeline.

 

One of the T-Splines, however cannot convert into a solid body because it has self intersecting geometry. That's when this bug occurs. This can easily be foxed by copying the 2 T-Splines each into their own separate T-Spline/Form features as shown in the screencast. Design is attached and should work.

 

 

 

Looking through the timeline of this design it is clear that this student is out of his depth and I. am wonder when he will get frustrated without guidance. 

 


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Message 6 of 9

Oli_Young
Enthusiast
Enthusiast

Thanks again for your kind instruction. I'll ensure that each T-spline has it's own element in the timeline in future. And thanks for the demo showing how to untangle the mess.

 

At the moment we are throwing stuff at the wall and seeing what sticks. Despite the muddle that some kids get into (!) it's a great leap forward in terms of generating aerodynamic models. 

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Message 7 of 9

jeff_strater
Community Manager
Community Manager

Sorry, I was out of town last week, so just getting to this today.  Perhaps I grabbed the design after it had already been fixed.  But, as near as I can tell with the version of the model I have, there are no orphaned bodies from TSplines in this model.  Perhaps, though, I am just missing the core issue here.  In general, it should be perfectly fine to have one Form feature which contains any number of TSpline bodies.  They should each get converted to a BRep body on exiting from Sculpt mode.  See the screencast below.

 

 

 

 


Jeff Strater
Engineering Director
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Message 8 of 9

TrippyLighting
Consultant
Consultant

The very first model in this thread exhibited this problem. Unfortunately I don;t have it anymore. But we did have this same problem in another thread if you remember.


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Message 9 of 9

Oli_Young
Enthusiast
Enthusiast

Sorry, it got kindly mended in the process! The images remain...

 

Thanks

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