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", which would be used if the animated texture could not be loaded.

Prior to the addition of actual animated textures, animations were procedurally generated. Placeholder textures were used for these blocks if the animation could not play. An easy way to see these in action (in some versions) is to enter the game while the game itself is paused (can be done if the window is out of focus when loaded), in which case the placeholder textures will be used.

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  ).

Placeholder texture for lava and water textures
The old lava and water textures from Alpha could be found in. The textures were replaced by different lava and water animations in 1.5.