I downloaded
the tilesets rescued from the Public Tilesets thread on the old forums a while ago, and finally got around to looking at using them today.
Among the tilesets I'm looking at using for
the Round Robin/Tundra group level, I found two by the same artist with less than half the tile space used in each, and which are visually compatible with each other. It would be simple enough to just copy and paste the tiles from one into the other, and edit the info line to reflect both sets' titles in addition to the artist's name. (There are, I noticed, many such... not necessarily incomplete, but definitely sparsely populated, tilesets among the ones Gaeel is so generously hosting.)
Unfortunately, the artist who created these particular tilesets, Johnny Chthonic, apparently hasn't been to the new forums at all. A forum search turned up a discussion of whether he was going to finish a level he'd been working up, but no comments by him -- unless he's using a different username now, but that seems like something that would've come up in the aforementioned discussion.
Since the questions my specific situation has raised also apply to other tilesets and other level designers wanting to use them, I decided to ask them here instead of PMing a mod to inquire after Johnny.
1) I know the tilesets on that 'Public Tilesets' page are usable without needing to request permission in advance (hence 'Public') but can they also be
modified without getting the artist's permission?
2a) In general -- that is, not only wrt the tilesets on that page, but any tilesets released for general use -- is it considered 'modifying' (and thus requiring permission, in cases where the artist hasn't specified that any and all editing are fine) to simply combine two tilesets by the same artist when this doesn't require leaving any tiles from either set out?
2b) What about putting a smaller number of tiles, say 1-6, from one tileset into a tileset with as many or more 'blank' / unused tiles by the same artist?
2c) I presume that regardless of permission requirement both tileset titles ought to be referenced in the info bar of the combined set, in cases where both entire sets are included; would both -- or potentially 3+ -- titles have to go there in the second case also? (That could be tricky to fit...)
3) I'm certain this has been answered (repeatedly, even) elsewhere, but so it's here with the other questions... Is the policy when an artist is AWOL and has released tilesets (or other level elements: music, COs, etc.) for public use but either not mentioned whether it was editable, or said to ask permission but can no longer be contacted, to "go ahead and use it with the understanding that if they come back and say no you'll have to take your level down and either replace their element(s) with something else or give up on re-releasing it"? Or is it, as with copyrighted / trademarked content from places like other (non-Nifflas, he seems reasonably easy to contact for yes/no permission purposes) commercial games, non-free songs, etc., the policy that "you can't use that without permission, and if you release without permission and are thus violating copyright, your level will be removed from the archive by an admin?"
The particular tilesets I'm looking at, for the curious, are Johnny Chthonic's 'Glass Maw' and 'Frozen Highlands'. If possible I was thinking about putting a handful of tiles from 'Dead Plains' and/or 'Underground Forest' that seem like they'd tie in nicely with the barren crystal/ice theme and also fit in the space
still left over after combining the first two.