Technique · rendering

Mosaic

A Super NES setting that draws a background in square blocks of a single color, for blurs and transitions.

stubAlso: mosaic effect, pixelation, block mosaicUpdated 2026-11-08
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  2. Games
  3. References
  4. Sources

Mosaic draws a background in square blocks of a single color. Final Fantasy VI starts a town or dungeon battle by stepping the size each frame through an HDMA table, blocks n + 1 pixels square for a size n, so the map breaks up twice into blocks up to 8 pixels and then once into blocks up to 161.

  • TransitionFinal Fantasy VI (1994). The battle mosaic's size per frame written through an HDMA table.1

See also

Games

GameYearHowNote
Final Fantasy VI1994Transitionthe battle mosaic's size per frame written through an HDMA table
Every claim about this mechanic, by game (2)
The Legend of Zelda: A Link to the Past 1991Three of the overworld's transitions (its submodules $0D, $17, and $24) darken and coarsen the picture together: they reset the fade counter to 0 with a target of 31, then each frame step the palette fade once and, on frames that find the counter odd, grow the mosaic size by 1, written with BG1, BG2, and BG3 enabled ($07) and BG mode value $09. Over the fade's 31 frames the size reaches 15, blocks 16 pixels square (computed), and the screen is then blanked. The transition back in, submodules $16 and $29, shrinks the size by 1 on odd counts in the same way.Code
Final Fantasy IV 1991On a town or dungeon map, a battle starts with sound effect $3F and 42 frames of mosaic before the field hands over to the battle program. The routine first leaves only BG1 and BG2 on the main screen, hiding the sprites, and then writes a 21-byte table to the mosaic register, each byte for 2 frames: the block size, on BG1 and BG2, rises and falls twice through 1, 3, 5, 7, 5 and 3 pixels square, then rises through 1, 3, 5 and 7 and on through 9, 11, 13 and 15 to 16. The same routine starts a battle that an event command or a scripted scene calls. Before it hands over, it reads the battle background from the map again, except for a battle a treasure chest starts.Code

References

  1. ^ abCodeeverything8215, FF6 disassemblybattle.asm 25–61, 65–68; reset.asm 287; +2 files
    How we know
    25; [ battle blur/sound ]
⋮
27.proc BattleMosaic
28        lda     $078a                   ; branch if battle sound effect is disabled
29        and     #$40
30        bne     :+
31        lda     #SFX::BATTLE_SFX
32        jsr     PlaySfx
33:       lda     $078a                   ; return if battle blur is disabled
34        bmi     Done
35        stz     $46                     ; clear frame counter
36Loop:   jsr     WaitVblank
37        lda     $46
⋮
    src/field/battle.asm lines 25–61 at 8130132 · upstream ↗
    65; [ execute battle ]
⋮
67.proc ExecBattle
68        jsr     BattleMosaic
    src/field/battle.asm lines 65–68 at 8130132 · upstream ↗
    287        inc     $46                     ; increment vblank counter
    src/field/reset.asm line 287 at 8130132 · upstream ↗

    4 more excerpts on the claim page

Sources

Code