one-prim tetrahedron ?

Hi. Do you know how to make a one-prim tetrahedron ?
(maybe out of a prism, or a cube ...?)
Sorry, I am not good with numbers, and I can't figure out the correct XYZ settings....

Thanks

Two simple options:

1. Start with a cube. Set the X taper to 1, and the Y taper to -1 (or vice versa).

2. Rez a prism (both tapers are set to 1 by default.) That's it.

Take your pick. The only real difference between the two is orientation. When both are at zero rotation, the cube will be standing on an edge, and the prism will be standing on a side.

On the "create" menu, the forth icon from the left, top row, is the tetrahedron prim. Merely click on it to select it, then click on the surface on which you wish to rezz a tetrahedron.

Thanks... hmm... sorry ! I should have been more precise :
I am trying to get a regular tetrahedron (with four equilateral triangles...).
I don't think I can get it with these two methods (unless I am making a mistake...?)


OK, using a prism, if I keep the X and Y seettings at 0.5 and reduce the Z setting at 0.333, its seems to be doing the trick...
But this is intuitive... I would like to be sure of the numbers, if possible...?

If you start with a cube that is 1.0 m square, then the face diagonal --- which will be one edge of the tetrahedron you create in it --- will have its length equal to SQRT (2) = 1.414 m. So, if you want a tetrahedron with all edges equal to 1.0, carve it from a cube that is 1/1.414 = 0.707 m on a side. Scale proportionately for the particular tetahedron you have in mind.

EDIT: Think of it this way.... If you carve a tetrahedron from a unit cube, its six edges are all face diagonals on the cube, and each has length SQRT(2). Therefore, the ratio of the tetrahedron's edge length to a bounding cube's edge is always 1.414/1. In your example, if you want the tetrahedron's edge to be 0.5 m, the cube's edges have to each be 0.354. Your intuitive guess of 0.333 wasn't far off. If you start with a prism, the way SL defines it, instead of starting with a cube, X=Y=0.5, Z=0.354.

I was able to do it both ways, with a cube and with a prism, using your measures... (0.333 was indeed a little off...

Thanks to everybody !