Hi Rick,
Another related issue.
I though my use of -volreg_opts_vr -maxdisp1D 'md_r${run}.1D' -1Dfile 'motion_r${run}}.1D' would let me name the dfile myself, but it only uses the second instance of the option -1Dfile.
3dvolreg -verbose -zpad 1 -base pb01_${subj}_r01_tshift+orig'[0]' \
-1Dfile dfile.r$run.1D -prefix rm.epi.volreg.r$run \
-heptic \
-maxdisp1D md_r${run}.1D -1Dfile motion_r${run}.1D \
-1Dmatrix_save mat.r$run.vr.aff12.1D \
pb01_${subj}_r${run}_tshift+orig
Not sure if you want to allow dfile to be renamed as I'm sure it is called a lot.
Hugo