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star tetrahedron

Posted: Wed Dec 30, 2009 9:57 am
by zeneteru
hi im looking for a star tetrahedron net, any ideas?

Posted: Wed Dec 30, 2009 11:22 am
by Ulrich
You load a tetrahedron and augment it with pyramids by hitting the "a"-key, chosing "augment by pyramids" and clicking "ok". The pyramids are indicated by spotted lines. Now you hit the ctrl-key and the left mouse key and pull the mouse to the right which increases the height of the pyramids to make them more spiky. You hit the "return"-key if the height is like you want it.


augment a octahedron

Posted: Fri Jan 01, 2010 5:08 pm
by zeneteru
Thanks for the reply. Better still is load a octahedron, augment it with pyramids on all sides then hit enter. Voila! a perfect star tetrahedron, then print out the nets...

Posted: Sat Jan 02, 2010 3:10 pm
by oxenholme
Wouldn't that give you Stella Octangula?

Posted: Mon Jan 04, 2010 1:17 pm
by robertw
Yes, I think a Stella Octangula is what was meant by star tetrahedron.

Another easy way to make one is to facet a cube. Enter faceting mode, with a faceting preview view open, and create a triangular facet using the three vertices that neighbour any vertex. The preview should show what you want, so accept it by clicking the left-and-down arrow above that view.

This way it is truly modelled as a compound of two tetrahedron.

Or better still, you'll find that it's already in the library provided with Great Stella/Stella4D. Stella Library->Compounds->Tetrahedra 2