Planar Quads Catenary

Replies to This Discussion

Permalink Reply by bea franko on July 1, 2015 at 9:01am

Permalink Reply by David Rutten on July 1, 2015 at 10:04am

Pretty sure those aren't planar.

Permalink Reply by Jens Pedersen on July 1, 2015 at 10:22am

you need to give edge freedom to move, otherwise you will never get them planar.. and Dave is right those panels in your image isnt planar, they look like ETFE cushions, which is a plastic, and is therefore not as problematic to use as glass... 

Permalink Reply by David Rutten on July 1, 2015 at 11:54am

Specifically if they were planar, then the diagonals of each panel would intersect at their midpoints, since all panels are symmetric as the bottom-up photo shows:

Permalink Reply by bea franko on July 2, 2015 at 3:32am

hey guys!

i know that these etfe panels are not planar.

but is it possible to make them planar, to make a cladding out of glas???

these picture are just to show the expexted result, as inspiration.

how to give them edge freedome?

Permalink Reply by Daniel Piker on July 2, 2015 at 5:27am

No, it is definitely not possible with this grid and boundary.
To see why, consider one of the panels in the corner - it has 3 points fixed in the plane of the boundary, 3 points define a plane, and for the panel to be planar, the 4th point must lie in this same plane. Therefore the 2 panels adjacent to this corner panel also have 3 points fixed in the boundary plane. Thus also their neighbours, and so on by induction the only way for all panels to be planar is if the entire mesh is flat and in the plane of the boundary.

To design a grid which can be planarized, try following the curvature directions of the surface.

Permalink Reply by Jens Pedersen on July 2, 2015 at 3:42am

try to allow the points to move freely in z, but then constrain them in x & y there is a component in Kangaroo that does this... 

Permalink Reply by Jens Pedersen on July 2, 2015 at 6:07am

Just to clarify, I meant the edge points :) 

Permalink Reply by bea franko on July 2, 2015 at 5:53am

it is possible, but not watertight;)

Permalink Reply by Marios Tsiliakos on July 3, 2015 at 6:24am

Hi Bea,

Please refer to the attached. I have played around with some of Daniel's K2 examples a few weeks ago. I had an example with the K1 solver but I can't seem to find it. It's  a proof of concept of what Daniel is mentioning. You need to have your boundaries to follow the curvature of the catenary, otherwise this is not possible.

Best,

M.

Attachments:

• 150703_relax_planarise_quads_MT.gh, 23 KB