How to manually specify the atomic block layout for voxelized domain?

Dear All,

I want to create a geometry based on stl file. For example, a cylinder with size of 60x60x120. I followed the example and wrote the code:

VoxelizedDomain3D voxelizedDomain(boundary, flowType, extraLayer, borderWidth, extendedEnvelopeWidth, blockSize);
MultiBlockLattice3D <T, DESCRIPTOR> *lattice= new MultiBlockLattice3D <T, DESCRIPTOR>(voxelizedDomain.getVoxelMatrix());

When I use 4 processor to run the above code, I found that the lattice is divided into 4 blocks with each size of 60x30x60. 

My question is how can I change the default block layout such that the atomic block size is 60x60x30? 

If I created a new lattice using my own layout such that each block is size of 60x60x30, Now the problem becomes that the lattice doesn't know the boundary of the cylinder. Does anyone have a solution to that? How can I change the default block size generated by voxelizedDomain3D? Thank you very much!

MultiBlockLattice3D <T, DESCRIPTOR> *lattice= new MultiBlockLattice3D <T, DESCRIPTOR>(MultiBlockManagement3D(blockStructure, threadAttribution, envelopWidth), defaultMultBlockPolicy3D().getBlockCommunicator(), defaultMultBlockPolicy3D().getCombinedStatistics(), defaultMultBlockPolicy3D().getMultiCellAccess<T,DESCRIPTOR>(), new BGKdynamics<T,DESCRIPTOR>(omega));