Unwinding plane

[Rummelplatz]

Hi there,

 

lately I am working a lot with the tool "unwinding plane" (don't know how it is called in english).

I encountered, that if it is a cylinder, everything is fine, but if this cylinder has something cut out,

the  plane is a little off on every side. Sometimes visible without zooming in.

So the problem is, I want to send this data to a laser cutter and it has to be a 100%.

 

Could someone explain why this is happening?

To me it is a more or less simple mathematical thing like pi*D. 

 

If you want to test it on your on, just create a cylinder and another one where you cut out something.

I used that same cylinder just flipped it 90degrees. 

 

Thanks in advance!

 

[Christiaan]

"Unfold Surface" is the name in English

[rDesign]

@Rummelplatz- before you ran the 'Unfold Surface' command, did you first either 1) convert the object to NURBS or 2) extract the NURBS surface?

[EDIT: I tried this as noted in the subsequent post below and got a complete Unfold failure].

 

That might give you better results, but historically the 'Unfold Surfaces' command has not been known to give 100% accurate results:

 

Edited June 1, 2017 by rDesign

[rDesign]

I recreated the object from the original post (a cylinder with a hole in it) and I cannot get the surfaces to unfold as far as Rummelplatz did:

 

I created two copies of this object, converted one to a NURBS surface by 'Convert to NURBS', converted the other by Extracting the NURBS surface.

'Unfold Surfaces' won't even attempt to unfold it:

 

IMO the 'Unfold Surfaces' command is completely broken if it cannot unfold this shape, which the error message implies it should be able to develop as it is literally the curved surface of a cylinder.

 

Vw2016 version attached.

cylinder_unfold_fail_2016.vwx

Edited June 1, 2017 by rDesign

[Kevin McAllister]

Mine unfolded without issue but I have the same sort of geometry errors in the unfolded polyline. I'm unsure whether to suggest bug submitting this or voting for a wish (I'm sure there's one somewhere, possibly posted by me). These types of digital manufacturing tools have become more and more important but they don't seem to be very high in the priority list for NV. The Unfold Surfaces command was added with the 3d Powerpack tools around Minicad 7 or so but they haven't had much love since. Maybe @JimW has some guidance about whether to wish list or bug submit. This is the second post about this command in a week.

 

Kevin

 

 

Edited June 1, 2017 by Kevin McAllister

[Rummelplatz]

22 hours ago, Christiaan said:

"Unfold Surface" is the name in English

thank you! 

[Rummelplatz]

21 hours ago, rDesign said:

@Rummelplatz- before you ran the 'Unfold Surface' command, did you first either 1) convert the object to NURBS or 2) extract the NURBS surface?

[EDIT: I tried this as noted in the subsequent post below and got a complete Unfold failure].

 

That might give you better results, but historically the 'Unfold Surfaces' command has not been known to give 100% accurate results:

 

Yes, I did both. Because it is not working when it is not a NURBS-Obj.

[Rummelplatz]

Thanks for all your comments!

I'm going to report this as a bug, because it is a very handy tool that should work propperly.

 

have a great weekand y'all!

 

 

[PVA - Admin]

22 hours ago, Rummelplatz said:

but if this cylinder has something cut out,

the  plane is a little off on every side. Sometimes visible without zooming in.

 

^ This is absolutely a bug ^

 

20 hours ago, rDesign said:

I created two copies of this object, converted one to a NURBS surface by 'Convert to NURBS', converted the other by Extracting the NURBS surface.

'Unfold Surfaces' won't even attempt to unfold it:

^ This unfortunately is Works as Designed for now until the capabilities of Unfold Surfaces are expanded. ^
 

[Kevin McAllister]

50 minutes ago, JimW said:

^ This unfortunately is Works as Designed for now until the capabilities of Unfold Surfaces are expanded. ^
 

 

Jim, I wonder if this dialog and the VW help should be updated to either give examples of CSG objects that can be acted upon by the command or be changed to say the command only works on NURBS surfaces. I have yet to find a CSG object that doesn't generate the error dialog and I'm pretty sure there aren't any.... 

Kevin

 

[PVA - Admin]

I think I have a request in for that from an earlier discussion, if not I'll pop a new one in today!