More Mirrormesh Issues

[JimZuber]

At the end of section 4.1.6 of the spec it states "If the producer chooses to do so, it MUST specify an empty triangles element, an empty vertices element and an empty trianglesets element for this mesh." There are several problems with this....

1)The trianglesets element is optional, so it doesn't make sense to require an empty triangleset as part of this requirement, although there is not harm in doing so.

2)In the beam lattice spec we allow beams with no triangle element defined although it is mandatory in the core schema, so unsure why we would require an empty triangle element here, although I guess it doesn't hurt anything. The consolidated schema was modified to make triangle element optional for test validation.

3)The schema requires a minimum of 3 vertices to be defined. Would need to make vertices have a minOccurs of zero in the consolidated schema we use for test validation

Not sure any action is needed, but just wanted to raise the issues.