Spherical Helix

[zenvoid]

Can anyone point me the right direction for modeling the shape shown in this image. It is going to be an actual graphic that gets applied to a 12" acrylic sphere. The flag strip is going to be 1.5" high.

 
I plan on unfolding the modeled shape, adding the flags to it and printing it.
 
Thanks for any help you can provide.
 
Ken Boyd
zenvoid design

 

 

https://drive.google.com/file/d/0B38jFKmIyHXdMDZJNXIyV0hpVjA/view?usp=sharing

[Tech]

Hi Ken,

 

Yes, one approach would be to intersect a sphere and a surface helix -- and then Slice the sphere with that surface.

 

Another approach for something like this can be found at the bottom of the v8 Tutorials here:

 

http://www.formz.com/support/downloads/tutorials.html

 

Once you have the shape, you need to Convert it to Facetted, and Triangulate all non-planar faces, and apply the texture map as desired.  Once you have it mapped, change the mapping type to UV Maps before unfolding.

 

Then you should be able to unfold it, but you may need to separate it into "gores" for best results, as per this tutorial:

 

ftp://ftp.formz.com/pub/formz/PDF_files/tutorials/compound_surface.pdf

 

Does that help?

[¢hris £und]

My tutorial 'could' use a refresh for the current version range.

The main difference is in selecting what you want to separate. Newer versions have the "segment sequence" option (not at my computer right now to look at what it is really called). This makes thing a lot easier than having to use the lasso tool.

If you are going to use faceted geometry to generate this, at least by the first method, you will need to reflow the geometry for this to unfold cleanly.

1. Generate the base object as Tech suggested
2. Select the outline "segment sequence"
3. Clear the outline of the inter-geometry. Using the "derive segments" tool with the "join Selected Segments" option chosen
4. Break the outline into two separate segmented lines at the poles or nearest you can get to what would be the poles
5. Polygonize tool to get a nice even spacing of your new mesh to be. Use a high number of segments.
6. C-mesh between the two lines. Oops, there is no c-mesh any longer. We would almost be done here if there were this tool in v8...

[Tech]

 Hi Chris,

 

Thanks for the additional info -- we will see if the C-Mesh can be restored in the future.  

 

As an update to this issue, Ken was able to get what he wanted from the suggestions that were posted above:

 

 

Hi Paul,
Wanted to thank you again for your help on that flag globe model.
They finished it up and it looks great. I put together this two page PDF
to show what I ended up doing.  You are free to use that PDF I sent for

anything you need. I know my unfolding was a bit on the luck side!
Thanks,
Ken

 

 

Great -- glad to help, Ken!  

[¢hris £und]

Tech,

 

IC  the ACIS unfolding appears to have been fixed.   Maybe,  Maybe I won't need the C-Mesh any longer.   Will need to experiment with them to see if this is the case.

 

I really would prefer to have the ability to unfold smooth objects.   

 

I will be in touch.!