🌕 Biome-specific gravity

BioGrav is a lightweight data pack that adds several categories controlled by biome tags which change mobs' gravity (and related attributes). Players experience these attribute changes smoothly: as a player gets closer to the biome, their gravity will change based on their proximity to the biome. Standing just on the border of a biome will not grant the player the full gravity change; to experience the full effect, a player must be surrounded by the biome by at least 4 blocks on all sides.

For performance reasons, mobs other than the player do not have smooth transitions and instead receive attribute updates which apply either the full gravity effect or no gravity effect depending on whether or not they are in the biome. These updates are applied to all mobs once per second, or to mobs closer to a player more quickly but inconsistently. This can be changed by adding mobs to the #biograv:smooth_transition entity type tag, although this may cause excessive TPS lag.

🔧 Customization

In the base data pack, all biome tags are empty, so no biomes will change mobs' gravity. This can be changed by applying the BioGrav Defaults data pack included in the version page, or by adding biomes to the following biome tags:

Biome tags

#biograv:kind_of_low_grav

Gravity: -60%
Step Height: +100% (1 block)
Safe Fall Distance: +200% (9 blocks)
Fall Damage Multiplier: -50%

#biograv:low_grav

Gravity: -83.3% (roughly the same gravity as the moon)
Step Height: +150% (1.25 blocks)
Safe Fall Distance: +500% (18 blocks)
Fall Damage Multiplier: -70%

#biograv:ultra_low_grav

Gravity: -90%
Step Height: +200% (1.5 blocks)
Safe Fall Distance: +900% (30 blocks)
Fall Damage Multiplier: -80%

#biograv:high_grav

Gravity: +50%
Jump Strength: +17.5% (jump height remains about the same)
Safe Fall Distance: -16.7% (2.5 blocks)
Fall Damage Multiplier: +100%
Movement Speed: -10%
Movement Efficiency: +0.025 (to make walking in soul sand less annoying)

#biograv:ultra_high_grav

Gravity: +100%
Jump Strength: +40% (jump height remains about the same)
Safe Fall Distance: -33.3% (2.5 blocks)
Fall Damage Multiplier: +200%
Movement Speed: -25%
Movement Efficiency: +0.1 (to make walking in soul sand less annoying)

❗ While it is possible, adding a single biome to more than one biome tag is untested and unsupported, and may yield unpredictable results. (Have fun!)

✨ Effects

Data packs or operators can use commands to specify particles and sounds for when players enter or exit a low- or high-gravity biome. These effects can be set by running functions:

Config functions

/function biograv:_config/effects/low_grav/enter/particle {id: "", pos: "", delta: "", speed: 1.0, count: 1, viewers: ""}

id: Type of particle (e.g. "minecraft:happy_villager")\ pos: Position of particle, supports relative or local coordinates (e.g. "~ ~0.05 ~", "^ ^ ^1")
-- Relative coordinates are from the player's feet, local coordinates are from their eyes
delta: Coordinate range particles spawn in
speed: Speed of particles
count: Number of partices
viewers: Target selector for who can see the particles (e.g. "@s" for only the player entering/exiting the biome)

/function biograv:_config/effects/low_grav/enter/sound {id: "", pitch: 1.0, volume: 1.0}

id: Sound event to play (e.g. "minecraft:block.stone.place")
pitch: Pitch of sound
-- Pitch is higher or lower depending on the gravity change (kind_of, ultra)
volume: Volume of sound

/function biograv:_config/effects/low_grav/enter {particle: {particle config}, sound: {sound config}}

Equivalent to running .../particle and .../sound functions with their respective config.

/function biograv:_config/effects/low_grav/exit {particle: {particle config}, sound: {sound config}}

Ditto, for exiting a low_grav biome instead of entering one.

/function biograv:_config/effects/low_grav {enter: {enter config}, exit: {exit config}}

Equivalent to running .../enter and .../exit functions with their respective config.

/function biograv:_config/effects/high_grav {enter/exit config}

Ditto, for high_grav instead of low_grav biomes.

/function biograv:_config/effects {low_grav: {low_grav config}, high_grav: {high_grav config}}

Equivalent to running .../low_grav and .../high_grav functions with their respective config.

❗ All fields for every function are required (i.e. you can't omit the count of a particle or the volume of a sound, you have to set them to something for the function to run properly). That means higher-level functions, especially biograv:_config/effects, are often too long to fit in the chat. If you're modifying the effects manually, use lower-level functions like biograv:_config/effects/high_grav/exit/particle with fewer arguments.

❗ Effects are only shown when entering/exiting biomes in the #biograv:effects biome tag, which is empty by default.

🧑‍🚀 BioGrav Defaults

BioGrav Defaults is a sample data pack included in the version page as a separate download. It is not necessarily intended for use in survival gameplay and merely serves as a reference for any data pack creators looking to implement BioGrav into their own projects. That doesn't mean it can't be used for survival, though.

🔥 The Nether

If you thought the Nether was a treacherous place already, get ready for a whole new challenge: finding your footing. Gravity in all Nether biomes is severely increased, throwing off the instincts of those used to the feel of the Overworld and making it an entirely different story to judge whether or not you can make that jump.

Curiously enough, the Soul Sand Valley seems to have even higher gravity than the rest of the Nether. Why that is, no one really knows, although maybe it has something to do with the biome's tortured past...

🌙 The End

When you enter the End, you'll immediately notice something different: you feel lighter. In the End, you can jump much higher, and step up blocks as if they were stairs. The dragon fight just got a lot more exciting!

The main island has the same gravity throughout, but the same can't be said for the outer islands. The voidscape of the greater End is filled with unpredictable gravitational anomalies. Approaching an archipelago of Small End Islands will allow you to bound between them with ease, but watch out for the empty gulfs of End Barrens surrounding them -- the not-so-low gravity there might put an abrupt end to your frolicking.