Builds a sphere by generating coordinates of points and also modifies
zoning by ratio-zoning point distributions. See the rz command for
more details. The itype
flag defines what type of sphere will be generated.
itype=1 generates a
sphere by gridding the faces of a cube and then projecting the vertices
onto a sphere. The number of nodes per shell is of the form 6*i**2.
itype=2 generates a
sphere by subdividing an icosahedron placed on the surface of a sphere.
Icosahedralm gridding is made up of 10 diamonds
per shell. Each diamond is made up of n**2 nodes (where n must be of the
form 2**i+1). There are 2 nodes (the poles of the sphere) at which 5 diamonds
meet and 10 nodes where 3 diamonds meet; hence there are a minimum of 12
nodes per shell. The number of nodes per shell can be 12, 42, 162, 642,...
itype= 1 or 2 or diamond
distributes points only, call connect to generate connectivity information.
nr is the number of
npt is the upper limit
of the number of points in a shell
itype=8 generates a
hexahedral icosahedron grid. This option distributes points and generates
the grid connectivity data structures.
xirad,xorad are the
inner and outer radii of the sphere. For itype=8 reverse inner and outer
xcen,ycen,zcen are the
coordinates of the center of the sphere
if =0 then
mins and maxs are used as cell centers
if =1 then mins and maxs are used as cell vertices
irat is ratio zoning
rz is ratio zoning value
- distance is multiplied by the value for each subsequent point.
itype = diamond
generates the points for one diamond of the icosahedron