Complete rework of parts and further questions

[Peter Blomberg]

The question remains, however, whether this primitive can be generated by two primitives 1-4disc.dat

1 4 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 1 1-4disc.dat
1 4 0 0 0 0 0 0 -1 0 0 1 0 1 0 1 0 0 0 1-4disc.dat

And, in this case, can the triangles be replaced by quadrilaterals?

Hi Manfred,

All disc primitives are made of triangles even if they could have used quads. Theoretically, disc primitives could also have been composed of chords and a base triangle, but that is a moot point since the primitives have already been created as they are.

Prims are generally not modified after initial creation. In this particular case, 2-4disc might have preceded 1-4disc and would thus not have been available at the time 2-4disc was created.

Now that both prims exist, you should use the prim that suit your pattern the best. In general, use the largest prim that suits your need instead of many smaller. It is your choice to use one prim or another and you should not need to think what is inside of them. Do not inline prims if you can use them as they are.