# Generating a mesh in NETGEN for the brick with non-standard boundary attributes

Hello,

I need a mesh for an orthobrick in [-1,1]^2 x [0,2] with the following boundary attributes:
1 for rectangles {-1<=x<=0, 0<=z<=2, y = -1} \union {x = -1, -1<=y<=0, 0<=z<=2}
2 for rectangles {0<=x<=1, 0<=z<=2, y = -1} \union {x = 1, -1<=y<=0, 0<=z<=2}
3 …
The idea is that looking from z axis, I want to specify four boundary parts which are related to four corners of the [-1,1] square in the base.

However, I didn’t find a way to do it in NETGEN. Can someone help me with that?

I tried something like
"
algebraic3d
solid subbrick1 = orthobrick (-1, -1, -1; 0, 0, 1) -bc=1;
solid subbrick2 = orthobrick (-1, 0, -1; 0, 1, 1) -bc=2;
solid subbrick12 = subbrick1 or subbrick2;
solid subbrick3 = orthobrick (0, 0, -1; 1, 1, 1) -bc=3;
solid subbrick4 = orthobrick (0, -1, -1; 1, 0, 1) -bc=4;
solid subbrick34 = subbrick3 or subbrick4;
solid cube4transport = subbrick12 or subbrick34;
tlo cube4transport;
"
but NETGEN failed when generating mesh at the step “Find edges”.

Thanks,
Kirill