Write out group name and material properties

Dear all,
I would like to solve the following task with your kind support.

I use Coreform Cubit as pre-processor, the mesh will be transfered into a seperate software for calculation purposes.

To wite out the mesh I use the following (or similar) code (only one group is shown as an example):

outucdfile = "D:\test.dat"
outfile = open(outucdfile,"w")

cubit.cmd("group 'temp_hexes' add hex all")
group_id = cubit.get_id_from_name("temp_hexes")

hex_list = cubit.get_group_hexes(group_id)
for hex_num in hex_list:
   hex_nodes = cubit.get_connectivity("Hex", hex_num)
   i = 0
   while i < 8:
      coord = cubit.get_nodal_coordinates(hex_nodes[i])
      outfile.write(str(coord) + "\n")
      i += 1

Defined group in Coreform Cubit
group_hexes = cubit.get_group_hexes(2)
q = len(cubit.get_group_hexes(2))
k = 0
while k < q:
      group_hexes_2 = group_hexes[k]
      outfile.write(str(group_hexes_2) + "\n")
      k += 1

Definition of material properties:
To define a material for volumes/hex which are part of a group I define blocks and name the blocks according to the materials (like Steel). As an example: The block “steel” containes then several group IDs.

Two tasks I would like to solve:

  1. Write out the group name, not only the ID
  2. Write out the material property of a group which is defined in a Block

It could look like in the output file:
Group name: Example
Group material: steel

Many thanks
BR Stefan

Hi @Stefan_R,

you can query the name and ids of the groups with cubit.group_names_ids()
After that you only need to search for your group id in the vector to get the group name.

Could look like this

group_id = 2
names_ids =  cubit.group_names_ids()
for pair in names_ids:
 if pair[1] == group_id:
  print("Group Name:" + pair[0])

For the Material you can first get the material id form a block and then query the material name.

block_id = 1
material_id = cubit.get_block_material(block_id)
print("Group Material:" + cubit.get_material_name(material_id))

Hi @Norbert_Hofbauer ,
many thanks for the supprt - works perfectly fine.

Hi @Norbert_Hofbauer ,
one question in addition came up:

  • Materials can be defined in coreform
  • Blocks can be defined and materials can be assigned to blocks
  • A block can contain groups.
    How can I read which groups are contained in a block?
    Many thanks!
    BR Stefan

Hi @Stefan_R,

normally you should be able to get a group list with


But unfortunately it currently throws me an error when i try this with the python api. I already informed the devs about this issue. Using the C++ version with the SDK would work

If you are using the python api for your process, it would be better to store the block group assignment in a global variable for later access. I currently don’t have a workaround for the missing function.

Hi @Norbert_Hofbauer,
happy new year!
Many thanks - please keep me updated if you receive an answer from devs.
At the moment I have solved the problem with a workaround, if possible I want to get rid of it with the help of “block.children()”
BR Stefan