vertex method
Adds a vertex; returns its index.
Implementation
int vertex(
double x,
double y,
double z,
double nx,
double ny,
double nz,
double u,
double v,
) {
_p.addAll([x, y, z]);
_n.addAll([nx, ny, nz]);
_t.addAll([u, v]);
return vertexCount - 1;
}