Apparently we lack a proper documentation for those. NSMBe's code isn't a great help there. Those were documented in old posts at Jul, but I don't feel like digging into the old threads to find them back. So I'll post my findings here.


Unused level #3 shows an interesting difference from other levels in the game: in its header, blocks 3 and 4 as twice as big as usual. The data in block 1 also exhibits a few oddities. We'll cover them a bit further in this post.

Unused level #3 is the one with the two large overworld areas and that weird little room inbetween them.

The room uses objects from tileset 2. If you copypaste that room into a level that uses a cave tileset, and change the objects to use tileset 1, it should give a perfect room.

The room was likely supposed to be using a cave tileset. And with that, a cave background. Explaining why the header's blocks 3 and 4 are bigger-- they contain data for two backgrounds and two tilesets.

Block 5 however only contains one entry. Supposedly the cave room wasn't supposed to have two backgrounds...


This feature could be interesting in NSMB hacks-- imagine being able to design subrooms with different tilesets all in the same level. No more bothering with restrictions imposed by the number of areas originally present (as long as both rooms can use the same sprite sets).

Except it seems to be broken. That unused level has garbled backgrounds ingame. And I don't know how the cave room's tileset would be handled as tileset 2 is used for the end-of-level castle.

I tried messing around with that feature, but couldn't get much interesting results so far.

First, a look at how the blocks are laid out:


Block 1


Blocks 3 (bottom BG), 4 (FG), 5 (top BG)


Block 8 (views -- doc from NSMBe)



The multibackground feature is glitched in that it always selects the background's tilemap ID from the last background block. Otherwise it seems to be selecting the other IDs from the right sources... to be confirmed.

Edit- bottom BG doesn't load if the view's bottom BG block ID is set to anything other than zero.
FG seems to always load from block 0 no matter what.
Top BG is broken the same way as bottom BG.

The tilemap ID of the view's top BG block is used to determine the color of the [?] blocks and such. This appears to be the only part of the feature that works correctly.


Edit-
The multiple BG feature is pretty much broken beyond repair. Or rather, only half of it is implemented. When switching between views, the game doesn't reload the graphics, except the jyotyu palette. Furthermore, the code that loads the palettes and tilesets always loads from the first BG/FG block, and the code that loads the tilemaps attempts to load all the blocks' tilemaps at the same place in VRAM.

Getting this beta remain to work would be too much work I guess.

Instead I'll keep this thread as a documentation for the NSMB level stuff that isn't very well documented.
_________________________
Kuribo64 - RH-fucking-cafe - Kafuka

zrghij