Wind + Gravity

Hello All,

I am trying to simulate the shingle facade of the Latvia Pavilion from the Shanghai Expo as an exercise in Kangaroo. I have done something similar in Maya, but thought I would give Kangaroo a go.

I have messed around a bit and got something that seems to be going in the right direction. This is more of a curiosity, but wanted to know if there would be a better way to approach it. I was thinking of solving this twice, first exert the "wind" force, solve, then use the output to exert the "gravity" force.

This is a super simple try, just using a point to describe the wind source...obviously an approximation. Any suggestions would be appreciated.

Attachments:

shingleWind.ghx, 311 KB

Replies to This Discussion

Permalink Reply by Daniel Piker on January 28, 2011 at 2:38pm

From what I can see in that video it looks to me like the shingles themselves have a very simple action (they are blown up by wind and fall back down with gravity), and really all the interesting part of the effect comes from the variations in airflow across the surface.

Maybe you could look at getting a vector field for the wind in from some CFD program, then you could have each flap be affected by the closest vector. Of course you really need a time varying vector field, which is trickier. You could perhaps import a static solution and add random time variation (though this should probably be somehow weighted more heavily in more turbulent regions).

I have been thinking to add a very simple wind force (similar to how pressure works now, but just projecting a wind vector onto the normal of the triangle and multiplying by the area). This wouldn't take care of what the wind vector should be, but it should allow things like flapping flags.

If I had a few months(maybe years) to dedicate purely to it I'd love to have a go at implementing actual real-time 3d fluids in Kangaroo, but I doubt that's ever going to happen!

Permalink Reply by Giulio Piacentino on January 28, 2011 at 2:45pm

Perlin noise is often used to give the effect of smooth but random variations in wind.
Maybe you could try using a Perlin-noise-based vector field?

- Giulio
_____________

giulio@mcneel.com
McNeel Europe, Barcelona

Permalink Reply by Daniel Piker on January 28, 2011 at 3:42pm

Yes that works pretty well!

Permalink Reply by Luis Fraguada on January 28, 2011 at 3:45pm

Nice, seems like a decent way to go... thanks for the suggestion.

Somehow all of us decided to hang in for the Fri night, Giulio, if Daniel was in town, I'd say lets go get a beer, but alas, its Raining in BCN!

Permalink Reply by Daniel Piker on January 28, 2011 at 3:45pm

Here's the definition.

Attachments:

shingles.ghx, 365 KB

Permalink Reply by Luis Fraguada on January 28, 2011 at 3:54pm

Nice combo! And yes, not too shabby!

Permalink Reply by Charles Sowers on February 25, 2017 at 9:44am

Hi I am relatively new to grasshopper and am trying to do a similar thing to the above. I just tried your definition and grasshopper cannot parse all the components and plug-ins needed. I have the latest Kangaroo(2.2.1) but grasshopper doesn't recognize the components in your definition. Where does perlin noise come from? In short how could I do this today? What do I need for it to work?

Thanks

Permalink Reply by Giulio Piacentino on February 27, 2017 at 3:16am

Perlin noise is probably from this component set. Kangaroo might have been in the 1.0 version, not the later 2.0 version.

Giulio
--
Giulio Piacentino
for Robert McNeel & Associates
giulio@mcneel.com

Permalink Reply by Necmettin on April 21, 2019 at 11:15am