bedrock_roof_position: The distance from the world height for the top coordinate of the bedrock roof, if out of world bounds (0-255) the roof does not appear, example: "-1". e.g. setting this to 32 puts the top of the roof at y=224. If the bedrock roof is low enough, natural terrain still generates above it. [needs testing]
bedrock_floor_position: The y coordinate of the bedrock floor, similar to bedrock_roof_position – setting both floor and roof to 255 generates a single layer of flat bedrock for each of them. [needs testing]
sea_level: The sea level in this dimension between 0 and 255
disable_mob_generation: Can be true or false. [needs testing]
structures: Structure settings
stronghold: Settings for how strongholds should be spawned. The stronghold values under the structures tag appear to be placeholders so that every namespaced structure has a value; these values are the ones that actually control stronghold spawning.
distance: Controls how far apart the strongholds are. [needs testing]
count: How many strongholds to generate. [needs testing]
top_slide: Settings for the curve at the top of the world.
target (integer): The value of the curve. Negative values round off the top of the hills in the affected area, positive values create a roof. Higher values produce larger effects.
size (integer): Defines the size of the affected area from the top of the world. size is calculated using the formula size = <height in blocks> * 0.25 / size_vertical.
offset (integer): Moves the affected area from the top of the world. offset uses the same formula as size, so offset = <height in blocks> * 0.25 / size_vertical. For top_slide, positive values move the area down and negative values bring it up.
bottom_slide: Settings for the curve at the bottom of the world.
target (integer): The value of the curve. Negative values remove the floor and round off the bottom of the islands, positive values make a floor. Higher values produce larger effects.
size (integer): Defines the size of the affected area from the bottom of the world. Uses the same formula as in top_slide.
offset (integer): Moves the affected area from the bottom of the world. Uses the same formula as in top_slide. For bottom_slide, positive values move the area up and negative values bring it down.
xz_scale (double): Scales the X and Z axis of the noise. Higher values results in more intricate horizontal shapes. Works similarly to coordinate scale from old customized worlds.
xz_factor (double): Smoothes the noise on the horizontal axis. Works similarly to main noise scale X/Z from old customized worlds.
y_scale (double): Scales the Y axis of the noise. Higher values result in more intricate vertical shapes. Works similarly to height scale from old customized worlds.
y_factor (double): Smoothes the noise on the vertical axis. Works similarly to main noise scale Y from old customized worlds.
size_vertical (integer): Changes the Y scale of the landmass. Values between 1 and 15 gradually increase the hill height, above 20 are all above the normal sea level of 63, and higher than 32 give normal land levels of 100+.[needs testing]
size_horizontal (integer): Changes the X/Z scale of the landmass, but not the biomes.[needs testing]
height (integer): Changes the max height of generated terrain by squashing the world. For example, with height=128, the ground is set to Y=32. this does not affect sea level.[needs testing]
density_factor (double): Changes the gradient of terrain density from the bottom to the top of the world. Positive values result in terrain that is solid underneath with shapes that shrink at higher altitudes, negative values result in terrain that is solid on top with empty space underneath. Greater positive or negative values result in a sharper transition.
density_offset (double; values between -1 and 1): Moves the center height for terrain density relative to Y=128, by an amount inversely proportional to density_factor.[needs testing]
island_noise_override (boolean; optional): Causes the world to generate like The End with a big island in the center and smaller ones around.
amplified (boolean; optional): Toggles between amplified and normal terrain generation. Can be used alongside large biomes in `vanilla_layered` types, and in any dimension (Nether, End, and custom).
↑Setting this to a number does not mean one structure is generated this often, only that the game attempts to generate one; biomes or terrain could lead to the structure not being generated. The maximum distance of structure placement attempts is 2*spacing - separation.
