In response to my previous question, the command line I was using was mris_flatten -1 -w 0 -distances 20 7 lh.occip.patch.3d lh.occip.patch.flat 

When I run this, the terminal output reads :

lh.occip.patch.3d no such file or directory. 

I followed all the steps to create the patch, and saved the file with tksurfer. I don't know what could be going on.