converting trimmed surface to untrimmed?

Replies to This Discussion

Permalink Reply by Anders Holden Deleuran on November 23, 2012 at 7:56am

The "Untrim" component does that.

Permalink Reply by kwanphil cho on November 27, 2012 at 3:24am

I think you misunderstood what I meant by converting trimmed surface to untrimmed surface. Often, we have problem with subdividing surface when it is trimmed surface since the original surface information is still there. I was just wondering if there is any way of getting rid of this information and becomes " the original " instead of lofting them.

Permalink Reply by Anders Holden Deleuran on November 27, 2012 at 3:40am

You did not exactly describe this issue in your original post, so no misunderstanding ;) 

The thing about NURBS surfaces is that they are defined as quad patches. So if your surface cannot be described within these constraints, you will will have issues using their UV subdivisions for anything meaningful. In your screenshot the trimmed surface now consist of five border edges, hence it cannot be converted/rebuilt into a "clean" singular NURBS patch. 

Depending on the specific situation and surface topology, you could use patch modelling or maybe consider using meshes (which may describe any surface) instead.

Permalink Reply by kwanphil cho on November 27, 2012 at 4:27am

Thanks for your relpy. Maybe you are right. I thought it was something quite obvious question if you are coming from architectural background. There were few threads discussing about the problem of trimmed surface when one tries to subdivide, some people suggested rebuild the surface by using network srf from rhino but I was wondering if there is way of converting to the surface that is more or less same as the rebuilt surface. I think this is extremely useful when one tries to populate the component in the surface. I don't know how patch modelling is helping this.

Permalink Reply by Anders Holden Deleuran on November 27, 2012 at 5:02am

"I don't know how patch modelling is helping this." See the attached file, it may provide an idea. The thing to be aware of is that it will result in a subdivision scheme for each patch, however, these do "align" so they can be used for panelling or whatever you're looking to further process.

Attachments:

• PatchModellingSurfaceDivision.gh, 7 KB

Permalink Reply by kwanphil cho on November 28, 2012 at 10:50am

Thanks a lot. I am not sure if I understood what you meant b patch modelling. Can you briefly explain to me how you generated the surface in your attached file? Thanks Anders in advance.

 

Permalink Reply by Anders Holden Deleuran on March 29, 2017 at 12:55am

FYI, you're replying to an almost five year old topic..