Invalid Surface ?

Hey there,

I'm having a an issue with the concept invalid surfaces. I'm using a script and i need to cut up an exisiting rhino surface ( not planar) into different smaller pieces using certain parameters. However using Surface Split component I sometimes keep getting and "invalid surface". And I cannot cut up this "invalid surface". Any pointers on how to get a normal surface, or even what this error means ?

Thanks in advance.

Replies to This Discussion

Permalink Reply by David Rutten on November 28, 2011 at 4:05am

Hi Carlo,

there's all kinds of things that could make a surface (especially a brep) invalid. If you feed the invalid object into the [Null] component, it will tell you why the shape is invalid. It's probably going to be a bit jargony, but if you post the results here I might be able to decipher it.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Carlor on November 28, 2011 at 9:14am

Hi again,

This seems to be the problem:

Surface: ON_BREP.m_T[2].m type = ON_BrepTrim::seam but m_iso is not N/E/W/S_iso.

thank in advance

Permalink Reply by Carlor on December 8, 2011 at 1:19am

bump

Permalink Reply by David Rutten on December 8, 2011 at 4:16pm

I'm not ignoring, I don't have any new information yet. This is clearly one of our bugs.

Can you post the files I need to replicate this? (and, does it also happen in Rhino5?)

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by FrankS on March 14, 2012 at 11:39am

Hi David, hi Carlo,

i ran into a case that sounds similar and attached an isolated reproduceable bug.

Choosing one specific edge of my Srf, I will constantly get an "invalid" result from the SrfSplit components. All others work fine.

I have no clue how to work around his. All hints welcome! Triming the srf directly with the pipes would be an option, but I don't see an component for that.

Hope this help to get the SrfSplit up and running. Or is there something wrong with the input srf that I don't see?

best ,

frank

Attachments:

SplitSrfBug_01.gh, 6 KB
SplitSrfBug_01.3dm, 660 KB

Permalink Reply by Guy Snover on April 27, 2012 at 1:47pm

other victims of invalid surfaces from split srf,

I just ran into the same problem, Spliting planar surfaces. I found that when I got the Brep edges, it had interior edges. When I baked out the edges It seems the one edge of the surface was not split by the splitting curve. Why? I dunno. This may just be my case, but if this happens the same way for you, It just took a little GH work to resolve that failed split and replace it in the data tree.

I don't have a repeatable file of the bug, but here's a snippet of how I created the split surface from the inavlid. Maybe it helps you apply a similiar fix to your surfaces?

Guy

gh 0.8.0066

Attachments:

invalid srf fix.gh, 16 KB

Permalink Reply by Dekani Fisher on October 29, 2013 at 1:16pm

when i was getting invalid surfaces from surface split

what worked for me was to use a brep|brep intersection component on my surface that was being split to create a curve. I then used this curve as in input for the surface split component... this still created an invalid surface however i then used the deconstruct a brep component which allowed me to extract my cutting curve as an edge... i then used this edge as an input on another surface split component on the same surface that was being split. this worked.

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