Procedural animated texture generation

Prior to Java Edition 1.5 snapshot 13w02a, the textures for animated blocks were generated on-the-fly using certain algorithms, rather than being defined image files.

Placeholder textures
Animated blocks and fluids had backup "placeholder textures" in terrain.png, overwritten in VRAM with the generated animations, which would be used if the animated texture could not be loaded.

In some versions, they could be triggered to appear if the game is paused upon first loading the world, which can be done by having another window which is not the game be in focus while the game loads the world.

It is worth noting here that flowing liquids use a texture twice the size of most block textures (32x32 as opposed to the usual 16x16). This is not unique to placeholder textures, and can also be noted when viewing the raw textures for liquids in 13w02a and above, as well as applying internally for generated liquid textures. A larger texture is used here since the texture is rotated accordingly to match the flow direction, while otherwise remaining at the same resolution. As a result, 16x16 textures would be too small to show a continuous texture if rotated at all, as with the most extreme case, a 45 degree rotation, there would be clear gaps at the corners, as one corner to the other would cross 16√2 pixels rather than 16.

When the generated animation was added for water in 0.0.19a, the old water texture used before that point was kept in for use as a placeholder texture.

A second copy of the water texture was added in the 20091223-1 Indev build, which was without a doubt linked to the addition of the flowing water texture.

In the 20100616 build of Infdev, the water placeholder textures were moved to the bottom-right of terrain.png. The still water texture remained as a single texture square, and the flowing water texture became a 2x2 square of water textures, as explained earlier.

With the addition of animated texture images in 13w02a, these textures were decommissioned and removed soon after.

The texture also existed in the terrain.png of early Pocket Edition, where it would be used as the water texture on certain devices, seemingly on either very new or very old devices relative to 2011-12.

The texture was also present throughout Legacy Console Edition's history, its use case unknown.

When the generated animation was added for lava in 0.0.19a, the old lava texture used before that point was kept in for use as a placeholder texture.

A second copy of the lava texture was added in the 20100110 Indev build, presumably for flowing lava, despite flowing lava not appearing visually distinct from still lava until the 20100616 build of Infdev. Whether this even represents where flowing lava would be at all, or if versions before 20100110 and inclusively after 20091223-1 would use the same placeholder texture for would-be "flowing" lava (in an identical situation to water) as it would still lava or if it would use the texture at this position instead which was a duplicate of the top of grass at the time, is currently unknown.

In the 20100616 build of Infdev, the lava placeholder textures were moved to the bottom-right of terrain.png. The still lava texture remained as a single texture square, and the flowing lava texture became a 2x2 square of lava textures, as explained earlier.

With the addition of animated texture images in 13w02a, these textures were decommissioned and removed soon after.

The texture also existed in the terrain.png of early Pocket Edition, and was used for all lava regardless of device up until v0.7.0 alpha, when lava became animated on seemingly all devices.

The texture was also present throughout Legacy Console Edition's history, its use case unknown.

The texture was also present throughout Legacy Console Edition's history, its use case unknown.

The texture was also present throughout Legacy Console Edition's history, its use case unknown.

Placeholder texture for fire


Placeholder graphics for the fire texture were found in, which was overwritten in VRAM with the true fire texture. The initial state of this texture was a vaguely flame-like red and orange scribble, but was later replaced with its second texture, a red square which read: "FIRE TEX! HNST", which means "Fire texture! Honest". It was replaced by the actual fire animation in 1.5.

A second copy was added to terrain.png in Beta 1.2, as fire now had two variant textures which would be variously applied depending on coordinates, this can be seen today in the fact that fire has two different texture files ( and  ).