To simulate grain growth during welding, without an initial microstructure representing base metal of welded material (each voxel begins with a randomly assigned spin), run spparks:
mpiexec -np 16 spk_mac_mpi < in.weldRandom
In this case, run the Potts model first:
mpiexec -np 16 spk_mac_mpi < in.potts3D
Then process the dump file to write another file called site.init. Run the script (no args).
write_site_init.sh
Then run the weld model using the in.weldRead input file in.weldRead, which uses the read_sites command rather than the set command to initialize an equiaxed grain microstructure:
mpiexec -np 16 spk_mac_mpi < in.weldRead