not able to generate planar surfaces from polylines

Replies to This Discussion

Permalink Reply by ng5 Alex on October 2, 2015 at 6:08am

are these polygon planar? you can check the using planar component found in tab curve/analysis

best

alex

Permalink Reply by Gaurav Goel on October 3, 2015 at 12:36am

i checked curves in rhino but they are not planar...but they seem planar like one rectangle in one plae...may be i dont understand proper definition of planar surface....

Permalink Reply by Gaurav Goel on October 2, 2015 at 8:27am

Yes these curves are planar because they have been extracted from flat mesh surfaces generated by panelling tools in grasshopper.

Permalink Reply by ng5 Alex on October 2, 2015 at 10:09am

without a file i cant think of something

Permalink Reply by David Rutten on October 2, 2015 at 10:25am

What's the warning on the Boundary component? You can see it if you click on the orange balloon.

Permalink Reply by Gaurav Goel on October 3, 2015 at 12:21am

Hi david I tried making faces from planar srf in rhino...and then I analysed the problem. It said that rhino needs closed planar loops for surface. Now those curves in lattice are all joined from straight lines I dont know why they are not planar. How to fix planarity issue of these curves. I am attaqching both of my files. I want to fabricate this form after I get these panels...

Attachments:

• rhino_curve_form.3dm, 176 KB
• shell_rectangle_panel_fabrication_ with_panel_number.gh, 12 KB

Permalink Reply by David Rutten on October 3, 2015 at 3:44am

Just because a curve is made from straight lines doesn't mean it's planar. The entire curve must exist in the same plane. This is an example of a polyline which is not planar

http://i.stack.imgur.com/s3D9v.png

Triangles are always planar, but anything with more edges might not be.

Permalink Reply by Gaurav Goel on October 3, 2015 at 4:32am

Thank you for that info...can you guide me on how I can turn those into planar curves.....I did that using flat panels in panelling tools also but then my panel edges won't meet each other...so I am little stuck

Permalink Reply by David Rutten on October 3, 2015 at 7:26am

Obviously you cannot make them planar without deforming them, so the question really is what parts of the structure are allowed to deform? Do you want to move a single point on each quad to make it planar? So you want to move two opposing points? Do you want to move all points? Do you need edges where adjacent quads meet to remain coincident? If you want the last one, that is really quite difficult, but there's a large body of work out there that deals with planarization/flattening, within Grasshopper your best bet is probably to use Kangaroo.

Permalink Reply by Gaurav Goel on October 3, 2015 at 2:24pm

Thank you David for that reply !