Funicular structures #2

Replies to This Discussion

Permalink Reply by Michael Makris on December 12, 2012 at 9:55am

Can you post your code?

Do you need to have Mesh as an input and output of Kangaroo? I have found oftentimes that no "Geometry" is needed. Also, turn off your Boolean toggle so that the simulation isn't constantly resetting. Your timer also seems way too long. 5 seconds is going to be really slow between iterations. Try like .1 seconds.

Permalink Reply by Paolo Bartoli on December 12, 2012 at 10:54am

Thanks Michael, 

I just updated the definition. It works with 50 mill sec.

What I don't exactly understand now is where are the anchor points are supposed to be: inside the mesh, with the same z axis value. That's how I placed them, but just two of them work as anchors, don't know why!

About the Boolean Toggle: what exactly activates the simulation? Can I get rid of Boolean Toggle?

Two more questions:

- can I use also curves or lines as "anchor points"?

- can I use Breps / Nurbs surfaces as inputs and outputs as well or do Kangaroo just works with meshes?

AFAIK the answer to both is no: anyone can correct me?

Thanks

Permalink Reply by Paolo Bartoli on December 12, 2012 at 10:55am

...here are the files !

Attachments:

• Catenary2.ghx, 95 KB
• catenary2.3dm, 118 KB

Permalink Reply by Michael Makris on December 12, 2012 at 1:02pm

Hey so I can't get Catenary2.ghx to open, it seems because you have the mesh pre-assigneed. Can you undo that so "mesh" turns orange and then resend this to me?

Also, where do "wbVertices" and "wbEdges" come from? I tried to recreate your code and I can't find those components...

As to the anchor points, I can't see which ones are selected there.... but are you sure it's all the ones you want? If so, then try flattening the data. If that doesn't work, try decreasing the "tolerance" of Kangaroo. Do that by using a "Kangaroo Settings" component from the Kangaroo toolbox. Set that up with the Kangaroo solver. Under the Tolerance input, change it from the default of .01 to .1. Sometimes it's so small that small rounding errors can mess things up.

Let me know, and resend me the GH file.

Permalink Reply by Paolo Bartoli on December 12, 2012 at 1:33pm

Micheal,

you need to install Weaverbird plugin into Grasshopper to have "wbVertices" and "wbEdges", download is here: http://www.giuliopiacentino.com/weaverbird/

I must admit that I don't (yet) know what exactly these last two plugin do. Just copied Daniel's .ghx to see and understand how Kangaroo works...

I'll try with tolerance settings and let you know what happens !

Permalink Reply by Michael Makris on December 12, 2012 at 2:02pm

So I think I've solved it. I think the big problem you're having is about the points. First, make sure you've selected all of them in your point component.

But most importantly, the points you've laid out in Rhino don't all actually fall on Mesh vertices. Zoom in close and you'll see that some are between vertices (see attached pic). Those that aren't correctly placed cannot be anchor points to the mesh, and so the mesh will ignore them and only be supported by those anchor points that are correctly placed. Fix the point positions and it should work like a dream.

Attachments:

• Mesh Fall Rhino.JPG, 149 KB
• Mesh Fall.JPG, 319 KB

Permalink Reply by Paolo Bartoli on December 12, 2012 at 2:20pm

Thanks, I was searching thru the documentation, but found no indications about where the anchor points should be...

Permalink Reply by Paolo Bartoli on December 12, 2012 at 2:06pm

About Weaverbird, as you read in Kangaroo's manual (sort of...), it becomes useful "to make sheet material..." and "Weaverbird has some very useful components for extracting the edges of meshes as curves. UTO's mesh tools are also very useful".