make_ggseg3d_2_ggseg expect bilateral atlas.

[drmowinckels]

Mostly unrelated to this issue, but perhaps a useful note to include for anyone who might make the mistake I just made: it looks like make_ggseg3d_2_ggseg() expects a bilateral atlas. The way I'd set up make_aparc_2_3datlas to run first, I had a list of atlases, with a separate ggseg3d-atlas dataframe for every hemisphere of every parcellation. When I went to run make_ggseg3d_2_ggseg(), steps 1-6 ran smoothly and then I got a funny error in step 7.

From debugging:

> atlas_df_sf <- ggsegExtra:::adjust_coords_sf(atlas_df_sf)
Error in atlas[[4]] : subscript out of bounds

Upon poking in, I realized I was meant to feed in a whole bilateral atlas to make_ggseg3d_2_ggseg() and that it was erroring out because it was looking for 2 hemispheres' worth of views and only finding 1. I combined the appropriate left and right hemisphere atlas dataframes, re-ran the function, and it worked all the way through! Hope this helps somebody else in the future.

Originally posted by @monicathieu in #27 (comment)