topic Re: Lofting with G2 continuity error in Inventor Forum

Lofting with G2 continuity error

Anonymous — Fri, 09 Dec 2016 04:25:53 GMT

Hi Everyone,

I'm having trouble creating this loft with a G2 continuity.
"The attempted Loft operation did not result in any meaningful result surfaces. Try with different inputs."
Any ideas about how I can get around this??

Thanks

Betreff: Lofting with G2 continuity error

WHolzwarth — Fri, 09 Dec 2016 09:58:45 GMT

No easy task. 2015 file attached.

Walter

Re: Lofting with G2 continuity error

PaulMunford — Fri, 09 Dec 2016 19:36:08 GMT

I'm guessing that the little edge at the top will be unfriendly. Try lofting each edge segment as a surface and see which edges will allow continuity and which won't.

Re: Lofting with G2 continuity error

WHolzwarth — Fri, 09 Dec 2016 20:38:39 GMT

Well, IMO Mikalo will run into another problem with trying to apply the red fillet.

Time will show.

Re: Lofting with G2 continuity error

jamesfgill — Tue, 13 Dec 2016 11:51:25 GMT

Hi Mikalo,

It’s difficult to make this part of the model with a G2 loft. The shape of the input geometry means that G2 loft will tend to make bad geometry that self-intersects. The algorithm detects the self-intersection and discards the bad geometry without you ever seeing it.

You can make this part of the model using a G2 patch:

The input to the patch is 2 loops. It's G2 with the solid model. I made it G1 with a cylinder at the circle sketch, otherwise it has the wrong shape.

To make a solid model I

deleted a face on the original solid model.
made a planar disc to cap the patch
stitched the patch and the planar disc into the solid model.

Re: Lofting with G2 continuity error

WHolzwarth — Tue, 13 Dec 2016 12:56:16 GMT

Oh, oh, James.

Not many people will be able to open 2017 Build 608 files.

Re: Lofting with G2 continuity error

jamesfgill — Tue, 13 Dec 2016 13:12:57 GMT

Hi Walter,

Thanks for pointing that out. I don't have a customer facing role, so I need help with these type of things.

I've remade the patch in an Inventor 2016 RTM that I had on another machine. I don't have easy access to an older build. If someone wants to see the patch in an older build, let me know.

Re: Lofting with G2 continuity error

Anonymous — Wed, 14 Dec 2016 08:21:29 GMT

Thank you everyone for your help. I have been super busy and haven't had the time yet to give it another go, but I'm sure I'll now have enough information to get it done. And if not, I'l know what to read up on.

Thanks again.