World Packets

Packets for world state synchronization — chunks, blocks, fluids, sounds, particles, weather, and time.

Summary

ID	Packet	Direction	Description
131	SetChunk	S->C	Chunk data (compressed)
132	SetChunkHeightmap	S->C	Chunk heightmap
133	SetChunkTintmap	S->C	Chunk tint colors
134	SetChunkEnvironments	S->C	Chunk environments
135	UnloadChunk	S->C	Unload chunk
136	SetFluids	S->C	Fluid data
140	ServerSetBlock	S->C	Single block change
141	ServerSetBlocks	S->C	Multiple block changes
142	ServerSetFluid	S->C	Single fluid change
143	ServerSetFluids	S->C	Multiple fluid changes
144	UpdateBlockDamage	S->C	Block damage state
145	UpdateTimeSettings	S->C	Time settings
146	UpdateTime	S->C	Current time
147	UpdateEditorTimeOverride	S->C	Editor time override
148	ClearEditorTimeOverride	S->C	Clear time override
149	UpdateWeather	S->C	Weather state
150	UpdateEditorWeatherOverride	S->C	Editor weather
151	UpdateEnvironmentMusic	S->C	Music state
152	SpawnParticleSystem	S->C	Spawn particles
153	SpawnBlockParticleSystem	S->C	Block particles
154	PlaySoundEvent2D	S->C	2D sound
155	PlaySoundEvent3D	S->C	3D sound
156	PlaySoundEventEntity	S->C	Entity sound
157	UpdateSleepState	S->C	Sleep state
158	SetPaused	C->S	Pause request
159	ServerSetPaused	S->C	Pause state
360	UpdateSunSettings	S->C	Sun configuration
361	UpdatePostFxSettings	S->C	Post-processing

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UpdateWeather

ID: 149 | Direction: S->C

Sends the current weather state to a player. Sent every 1 second when weather changes, with a transition duration for smooth blending.

Field	Type	Description
weatherIndex	int	Index into the weather asset table (0 = unknown/none)
transitionSeconds	float	Transition duration in seconds (0.5 on join, 10.0 on change)

Fixed size: 8 bytes. Not compressed.

API: See Weather

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UpdateEditorWeatherOverride

ID: 150 | Direction: S->C

Overrides the weather display for asset editor previews.

Field	Type	Description
weatherIndex	int	Weather asset index (0 = clear override)

Fixed size: 4 bytes. Not compressed.

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SpawnParticleSystem

ID: 152 | Direction: S->C

Spawns a particle effect at a world position with optional rotation, scale, and color.

Field	Type	Description
particleSystemId	string	Particle system asset ID (e.g. "Hytale/DirtBreak")
position	Vector3d	World position
rotation	Vector3f	Yaw, pitch, roll in radians
scale	float	Scale multiplier (default 1.0)
color	Color	RGB color override (null = no override)

API: ParticleUtil.spawnParticleEffect()

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SpawnBlockParticleSystem

ID: 153 | Direction: S->C

Spawns a block-specific particle effect (walk, break, hit, etc.). Sent to all players with the chunk loaded.

Field	Type	Description
blockId	int	Block type ID
particleType	BlockParticleEvent	Event type (Walk, Break, Hit, etc.)
position	Vector3d	Block position

API: Triggered by WorldNotificationHandler — see Block Particles

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PlaySoundEvent2D

ID: 154 | Direction: S->C

Plays a non-positional sound directly in the player’s audio output.

Field	Type	Description
soundEventIndex	int	Sound event index (from SoundEvent.getAssetMap().getIndex())
category	SoundCategory	Audio bus (Music, Ambient, SFX, UI)
volumeModifier	float	Volume multiplier (default 1.0)
pitchModifier	float	Pitch multiplier (default 1.0)

API: SoundUtil.playSoundEvent2d()

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PlaySoundEvent3D

ID: 155 | Direction: S->C

Plays a positional sound at a world location with distance attenuation.

Field	Type	Description
soundEventIndex	int	Sound event index
category	SoundCategory	Audio bus
position	Vector3d	World position
volumeModifier	float	Volume multiplier (default 1.0)
pitchModifier	float	Pitch multiplier (default 1.0)

API: SoundUtil.playSoundEvent3d()

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PlaySoundEventEntity

ID: 156 | Direction: S->C

Plays a sound attached to an entity that follows it as it moves.

Field	Type	Description
soundEventIndex	int	Sound event index
networkId	int	Entity network ID
volumeModifier	float	Volume multiplier (default 1.0)
pitchModifier	float	Pitch multiplier (default 1.0)

API: SoundUtil.playSoundEventEntity()