A very quick and cheap visualisation method for skymaps. Print out 1’s and 0’s, choose a text editor of your choice without line break, turn down the font size and voilà

Very cheap and quick visualisation for the poor man.

UPDATE - Here’s a suggestion for a ASCII opacity table:

 .,'~:;!+>=icopjtJY56SB8XDQKHNWM

Thanks to goliath who has extracted the ASCII opacity table somewhere from irrlicht.