Rhino help

#1

I wonder if someone could help me solve this problem. Rhino has a good command called unrollsurf for developable surface. This is very useful if someone need to build a physical model out of the Rhino 3d model. However, it would be great if there’s a command that works in reverse. I have build a physical model that has a rectangular skin that wraps around a structural support very much like a piece of rectangular paper wrapping around a cone. But to try to build this tapered cone-like shape (that still keeps its rectangular property without distortion) is imposible for me with the existing commands. I tried using sweeps around a tapered spiral but does not work (does not unroll into perfect rectangle). I need help!

#2

It would help if you posted a sketch just so we can see your initial idea.
Cones do not unroll this way…to a rectangle,
http://newsletters.hagerman.com/newsletters/ebul49-Tips.htm
You can fit a rectangle in the the space it makes but there will be some odd left over shapes.
-If you are trying to glue/map a rectangular image onto the cone shape without distortion it will not work.

#3

Hi Cloneops,
I would like to post an image but am not sure how to do this. The image is a physical model I did that shows a tower wrapped in a rectangular piece of skin thats slightly tappered and cone shaped. I’ll find out how to post an image in this forum.

#4

see image below

#5

Here is an image of what I was talking about. It was a project I was working on 3 years ago and I started out by building a physical model by using a rectangular metal sheet for the tower’s skin. Later I tried modelling the tower in a program called Vectorworks. After failing to do it correctly I had posted the same problem on a Vectorworks forum and someone really clever has helped me written a script for a command. This command would draw the skin in 3d model after the user inputs the pitch and rotation and base width etc. I have no experience in writing script but perhaps this is the only solution.

#6

In Rhino4 use the “splop”:slight_smile: command, that should work!

#7

If the supporting structure is symmetrical, in the real world, the sheet once is wrapped around it, only intersect at the pylons. if you create the same structure in Rhino and then a cone with the same dimensions in diameter, you can then trim the cone to achieve the wrap, later placing it on the structure, and you should have the same effect

#8

Hi,

Thank you all for the reply. I will give splop a try. However, I think the challenge of the project is not to creat a “look alike” of the physical model but that the rectangular shape will retain its geometry when “rolled” into shape. The hard part is not only is the shape developable but remains a rectangle without distortion!

#9

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