[pstricks] strange behavior in pst3d-solides

[Zbigniew Nitecki]

I am trying to create a macro to draw a double cone which is "split open" to allow the viewer to see objects inside.
The attached test code

results in the following picture:

I should point out that the two pieces of the cone are drawn by two different loops within the "faces=" part of the pst object.
The only difference between the two loops are the limits on "k", which counts the "levels" of faces (each is a conic fulcrum);
previous to that the "sommets=" part plots vertices all the way down.  My counting skips the two middle levels, as the vertex
calculation leads to faces with two identical vertices, and I want to deal with the consequences of that later.

My problem is:  the top cone has the "open cut" in one position while the bottom one has it on the opposite side, even though
the counting is identical for a given value of "k".  Can anyone help me understand what is happening?

Zbigniew Nitecki
Department of Mathematics
Tufts University
Medford, MA 02155

telephones:
Office    (617)627-3843
Dept.    (617)627-3234
Dept. fax    (617)627-3966
http://www.tufts.edu/~znitecki/

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