After practicing making the 5 platonic solids, using Michaels method of
twin, vertical, intersecting rotation circles, strategically centered, perpendicular to an objects axis of rotation,
and passing through the vertex to be joined, http://moi3d.com/forum/index.php?webtag=MOI&msg=2140.46
it was very easy to construct a geodesic dome. It was not necessary to use any dihedral angles.
Rotate axis and Array Circular were used multiple times.

The variety of geodesic dome was selected from here: http://simplydifferently.org/Geodesic_Dome_Notes?page=3
It is called the "3V 5/9 Icosahedron Dome." This dome is made up of 3 different lengths of materials, in the form of line
segments, which form two different isosceles triangles.

(I build one out of 2x4's and plywood, a number of years ago, long since rotted away...)

Or you can just import a model from somewhere...







The top "4/9ths" of the dome can be copy rotated about the top pentagonal vertex, and moved vertically downward,
to create the full "spherical" dome.

bemfarmster!

Quite interesting modeling topic!

I had a similiar problem a couple of days ago to find a way to
distribute spheres on a large sphere, equally spaced and thought
to use a subdivided geodesic dome for this task. Later i figured
out that there's a script to takle circles distribution on a sphere.

Now i wonder if you, since you have programing skills, or someone
else has already tried this interesting problem as script for MoI,
like the one for Rhino.

http://mirye.net/forum/7-shade/571-a-challenge-for-the-experts

Regards
Stefan

Hi Stefan, what does the Rhino script do, does it just apply a copy of an object to every vertex of the mesh?

If so then I think you should be able to do that in MoI too - convert the polygon mesh file to OBJ format and then use the OBJ to 3DM wireframe converter from here: http://moi3d.com/wiki/Resources#Obj23dmWireframe_converter then import the 3DM file into MoI, you will now have a bunch of lines.

Select the lines and turn on their control points, then you want to select all control points but not the lines themselves which you can do with a little trick - first do a Ctrl+A to select everything (this will select both control points and the lines too), then go to the Scene browser Types > Curves section and click on the yellow dot there to deselect the lines - this will now leave only all control points selected.

Then with all control points selected do a Ctrl+C and a Ctrl+V - this will duplicate the control points as regular point objects, and then with a bunch of point objects you can use Petr's CopyToPoints plug-in from here: http://kyticka.webzdarma.cz/3d/moi/#CopyToPoints which will allow you to replicate an object onto all those point locations.

One thing to watch out for is that you will probably have duplicated points though. If you want to avoid duplication, it might actually be easier to extract out the vertices from the OBJ file, they are all the lines that begin with a plain v, like this:

v 9.35988888 0.00000000 7.58456939
v -5.86619529 0.00000000 7.58456939
v -5.86619529 0.00000000 -7.64151478
v 9.35988888 0.00000000 -7.64151478
v 9.35988888 11.67774935 7.58456939
v -5.86619529 11.67774935 7.58456939
v -5.86619529 11.67774935 -7.64151478
v 9.35988888 11.67774935 -7.64151478

If you extract out all those lines to their own text file and then use search & replace in a text editor to strip off the v at the start, you will then have a points file that could be imported using Petr's ImportPointFile plug-in: http://kyticka.webzdarma.cz/3d/moi/#ImportPointFile

- Michael

Hi Michael,

>Hi Stefan, what does the Rhino script do, does it just apply a copy of an object to every vertex of the mesh?

No, It actually places circles equally spaced from each other onto a NURBS sphere.

You can find the script in the sample folder and in the .pdf documentation on page 63.

http://wiki.mcneel.com/developer/rhinoscript101

Best regards
Stefan

Hi Stefan,

> No, It actually places circles equally spaced from each
> other onto a NURBS sphere.

Ok, I see - I think it would be possible to translate that script into MoI, but since it already exists and is all working within Rhino why not just use Rhino to run it and then you would have what you need?

- Michael

Appears scriptable, but would not produce a "perfectly" equal spacing. I don't think a perfect spacing is possible,
except for the 5 platonic solids. (??)

Hi Michael,

i used Rhino 4 (eval) to do the sphere, so no need for me for a MoI script. It was only a thought.

bemfarmer, thanks for the interesting link!

Best regards
Stefan