Hello to everybody on this list.

First time a big sorry for my bad english. I have problems to learn the english

language.

Thanks for your understanding.

I'm learning OpenSCAD since a few days.

I wrote a simple code in OpenSCAD

This module is a part in a library.

--- tripy.scad ---

// module for a library

module triangle_pyramid_base(length, height)

{

a=sqrt((length * length) - ((length / 2) * (length / 2)));

polyhedron(points=[[(length/2),-(a/2),0],[-(length/2),-(a/2),0],[0,(a/2),0],[0,0,height]],triangles=[[0,1,2],[1,2,3],[0,1,3],[0,2,3]]);

}

triangle_pyramid_base(10, 20);

------------------

If i press the F5-button for "compile", two facets are purple.

If i press the F6-button for "compile and render", the view-windows is empty and

i get this message:

CGAL::Polyhedron_incremental_builder_3<HDS>::

lookup_halfedge(): input error: facet 1 shares a halfedge from vertex 0 to

vertex 1 with facet 0.

I don't have an idea what the problem is. I'd searched with google for an answer

but i don't find it.

Can you help me?

Thank you.

T1nt@n

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