20091210

Planar Panels: 2 Ways to Get Flat


A recurring question I have gotten: "is there any way with the 2010 Massing tool set to make Curtain Panels that are always flat?" A couple ways.

[Edit: I have posted a better way for quad panels here: http://buildz.blogspot.com/2009/11/planar-panels-3-point-invisible.html]

Option 1
Real Triangle:
Curtain Panel by pattern templates have a number of basic pattern, one is called “Triangular”. Curiously, this panel is made up of four points, and some users find it vexing. There is an explanation for this, just not a very good one, and it's boring. If you want to make your panel behave like a real triangle (always planar), grab the middle, extraneous point
and pull it vertically up off the grid,

Connect the remaining points by a reference spline by points, and proceed to forget all about the extra point.



Voila, faceted surface with triangles!

But planar triangles are too easy to design and too expensive to build. How about something more challenging?

Option 2
Planar Quadrilaterals:

Go into the shipped content in the curtain panel by pattern folder and load "Planar Face". If your faces are relatives small, they will always be planar on the top surface. This panel does some freaky things with the panel paradigm.

If you open the panel and select the geometry, you will see that it's actually a tall blend with a void slicing off the top.



This void is hosted on the Level 1 workplane, which, when loaded into the family, approximates a "best fit" normal plane for the four panel points. The practical upshot of this is that you get a stable plane that will always shear off your blend with a nice planar face. There are 2 notable limitations to this panel. If your panel is too big, the void will not shear off the face completely. This can make for some interesting results, but probably not what you are going for. To correct this, just make the void much wider. The second problem is that for really distorted panels, the void will sometimes shear off the corners or mid section. But sometimes this is good too.


I was originally messing around with this stuff trying to knock off Norman Foster's Smithsonian roof:

But you can also make a mean Sonic the Hedgehog.

4 comments:

  1. Hi, I did some tutorials on ensuring planarity for my students at RMIT a while ago. they are about half way down this page. -->

    http://www.notionparallax.co.uk/blog/index.php/tutorials/

    Good to see this coming up in revit now!

    ReplyDelete
  2. hi
    I have a question
    in Norman Foster's Smithsonian roof the panels are all with the same dimensions?
    is there any way to force "same dimensions" on nurb surfices in revit 2010?
    thnx

    ReplyDelete
  3. Kubbah,
    Unfortuately, the short answer is no. I've done a couple posts that discusses this to some strategies to limit or control panel size and planarity. I'll do some more posts on this in the future, as it is a recurring question and there are a number of strategies. However, even conceptually, there is no "easy button" to just make all panels the same on a complex surface.
    http://buildz.blogspot.com/2009/06/rationalizing-panels.html

    http://buildz.blogspot.com/2009/07/limiting-panel-size.html

    ReplyDelete
  4. thnx! Great blog BTW!
    a question:
    Is the Norman Foster's Smithsonian roof done with all different panels? or the foster's panels are standardized in some way.. (and if they are standardized, is there any other software which parametrizes this kind of curves better? )

    thnx for ansers, and have a good day ;)

    ReplyDelete