Since I've recently been working on some Minecraft world gen stuff I came across Minecraft's internal height maps. I mainly
needed them for a few placement modifiers like the surface_relative_threshold_filter.
I couldn't find any documentation on the different heightmap types, so I decided to dig into Minecraft's code and write
a small program that can render them. Here's a small overview:
Minecraft has 6 different heightmap types:
WORLD_SURFACE_WGWORLD_SURFACEOCEAN_FLOOR_WGOCEAN_FLOORMOTION_BLOCKINGMOTION_BLOCKING_NO_LEAVES
The heightmaps with the _WG suffix are used for world generation and aren't present after a chunk has been generated.
They're pretty much the same as the ones without the suffix. Of course, some data might still be missing in the _WG
heightmaps since they're still being generated.
The WORLD_SURFACE heightmap stores the height of the highest non-air block in each block-column.
Same as WORLD_SURFACE but all non motion-blocking blocks (water, lava, flowers, etc.) are ignored.
Same as OCEAN_FLOOR but fluid blocks aren't ignored.
Same as MOTION_BLOCKING but leaves are also ignored.
Here are some examples of the different heightmaps (click the arrows):
Since all non ocean floor heightmaps are the same for this example, I only included the ocean floor and world surface heightmaps.
Screenshot
World surface
Ocean floor
Seeing the difference between WORLD_SURFACE and MOTION_BLOCKING might be hard on some monitors since only a few pixels
have a 1 gray level difference. You can open them in full screen and switch between them to see the difference better.
Hi, is the program linked on this document?