View override & sensing · let one player see something different / work out what device they use¶

view* only changes the client view: on one player's (or every player's) client, an entity or a block looks different, while the server-side world, the save, collision and what other players see all stay as they were. sensing* looks up a player's current input device (keyboard-mouse / touch / gamepad / motion), and the most common use is routing the interface by device: touch gets the virtual container, keyboard-mouse gets the trade menu.

Overrides live only in the server's memory: a restart loses them, but an override recorded by player name still applies after that player rejoins. Neither view* nor sensing* has events or a polling queue — call directly and get the result directly.

Quick start¶

const viewEntity     = ll.import("HologramLib", "viewEntity");
const viewBlock      = ll.import("HologramLib", "viewBlock");
const viewSelfType   = ll.import("HologramLib", "viewSelfType");
const viewUniqueIdOf = ll.import("HologramLib", "viewUniqueIdOf");
const viewClearAll   = ll.import("HologramLib", "viewClearAll");

// entity 12345 becomes a cow for Steve, with the nametag "§cDairy cow" always shown
viewEntity("Steve", 12345, "type=minecraft:cow;name=§cDairy cow;always=1");
// (100,64,100) shows up as a diamond block on Steve's client
viewBlock("Steve", 100, 64, 100, "minecraft:diamond_block");
// make everyone see Steve as a zombie
viewSelfType("Steve", "minecraft:zombie");

// getting someone else's uniqueId: only -1 means offline (the uniqueId itself may be negative, so do not write < 0)
const uid = viewUniqueIdOf("Alex");
if (uid !== -1) viewEntity("", uid, "type=minecraft:cow");   // everyone sees Alex as a cow

viewClearAll("");   // wrapping up: clear every player's overrides

The spec string¶

viewEntity / viewSelf's spec is separated by semicolons, with each item written key=value; keys are case-insensitive, and whitespace around values is trimmed.

Key	Value	Notes
`type=`	an entity type name	swap to that type (a bare `cow` becomes `minecraft:cow` automatically); for a player entity = build a mob stand-in for them with the same id
`as=`	an online player's name	display as that player (the skin comes from them); only works on player entities
`skin=`	a registered skin id	swap to a skin from the registry (registered by `playerNpcRegisterSkin` / `playerNpcCaptureSkin`); only works on non-player entities — the client renders it with the player model, while server-side it is still the same mob
`hidden=`	`1` / `true` / `yes` / `on`	hide this entity from that player
`name=`	nametag text	the nametag is changed as soon as this key appears; an empty value = clear the name
`always=`	`1` / `true` / `yes` / `on`	the nametag is always shown (use it together with `name=`)
`pose=`	`0..13`	the pose index; out-of-range values are clamped into range; the client only poses armour stands and players from it
`scale=`	`0.0625~10`	the metadata scale (client entity scale + hitbox); out of range and the whole item is ignored; not the same thing as the `skin=` tier's model scale
`variant=`	integer	the variant: the sheep's colour tier / the pufferfish's puff state (`0` normal `1` half-puffed `2` fully puffed) / the tropical fish's body shape …
`mark=`	integer	the second-level variant (may also be written `markvariant=`): tropical-fish patterns `0..5`, horse markings and so on
`color=`	`0..15`	the main colour (may also be written `colorindex=`); out of range and the whole item is ignored
`color2=`	`0..15`	the pattern colour (for tropical fish); out of range and the whole item is ignored

pose= / scale= / variant= / mark= / color= / color2= are additional items, and have to be given together with a main item (type= / as= / skin= / hidden= / name=): a spec with only additional items counts as "no effective item at all", which is the same as withdrawing that override.

Main entry points¶

Override an entity as one player sees it¶

viewEntity(playerName, entityUniqueId, spec)

Parameters:
playerName : String
the player's name; an empty string = apply to every player
entityUniqueId : Integer
the entity's unique id — for a player take it from viewUniqueIdOf, and for other entities from Entity.uniqueId (convert it to a number with Number(e.uniqueId))
spec : String
the override content, see "The spec string" above
Return value: true = it was registered; false = the spec has no effective item (this call then equals withdrawing the override, and false if there was no override to begin with)
Return type: Boolean

Example:

const viewEntity = ll.import("HologramLib", "viewEntity");
viewEntity("Steve", 12345, "type=minecraft:cow;name=§cDairy cow;always=1");
viewEntity("Steve", 12345, "hidden=1");   // let only Steve be unable to see it

Override a block as one player sees it¶

viewBlock(playerName, x, y, z, type)

Parameters:
playerName : String
the player's name; an empty string = apply to every player
x : Integer
the block coordinate X (integer)
y : Integer
the block coordinate Y (integer)
z : Integer
the block coordinate Z (integer)
type : String
the block id, such as "minecraft:diamond_block"; an empty string = withdraw the override at this coordinate
Return value: true = it was registered; false = the type name is not in the client's registry (when type is empty, false = this coordinate had no override to begin with)
Return type: Boolean

Example:

const viewBlock = ll.import("HologramLib", "viewBlock");
viewBlock("Steve", 100, 64, 100, "minecraft:diamond_block");
viewBlock("Steve", 100, 64, 100, "");   // withdraw this block

Withdraw one entity's override¶

viewClearEntity(playerName, entityUniqueId)

Parameters:
playerName : String
the player's name; an empty string = apply to every player
entityUniqueId : Integer
the entity's unique id
Return value: true = it was withdrawn and restored; false = there is no such override
Return type: Boolean

Example:

const viewClearEntity = ll.import("HologramLib", "viewClearEntity");
viewClearEntity("Steve", 12345);

Withdraw one block's override¶

viewClearBlock(playerName, x, y, z)

Parameters:
playerName : String
the player's name; an empty string = apply to every player
x : Integer
the block coordinate X (integer)
y : Integer
the block coordinate Y (integer)
z : Integer
the block coordinate Z (integer)
Return value: true = it was withdrawn and the real block pushed back; false = this coordinate had no override to begin with
Return type: Boolean

Example:

const viewClearBlock = ll.import("HologramLib", "viewClearBlock");
viewClearBlock("Steve", 100, 64, 100);

Withdraw every override for one player¶

viewClearAll(playerName)

Parameters:
playerName : String
the player's name; an empty string = all players
Return value: no return value
Return type: Null

Example:

const viewClearAll = ll.import("HologramLib", "viewClearAll");
viewClearAll("Steve");   // clear Steve only; passing "" clears the whole server

The "self" family¶

This group acts on the caller themself and is shown to every player (for things like an admin disguising themselves or an event transformation).

Put an override on yourself¶

viewSelf(playerName, spec)

Parameters:
playerName : String
the player's name, who must be online
spec : String
the override content (the same as viewEntity, see "The spec string" above)
Return value: true = it was registered; false = the player is offline, or the spec has no effective item
Return type: Boolean

Example:

const viewSelf = ll.import("HologramLib", "viewSelf");
viewSelf("Steve", "type=minecraft:cow;scale=0.8");   // everyone sees Steve as a small cow

Withdraw your own override¶

viewSelfClear(playerName)

Parameters:
playerName : String
the player's name
Return value: true = it was withdrawn; false = the player is offline or there was no override to begin with
Return type: Boolean

Example:

const viewSelfClear = ll.import("HologramLib", "viewSelfClear");
viewSelfClear("Steve");

Make yourself look like another mob to everyone¶

viewSelfType(playerName, type)

Parameters:
playerName : String
the player's name
type : String
an entity type name, such as "minecraft:zombie" (player and mob types both work)
Return value: true = it was registered; false = the player is offline
Return type: Boolean

Example:

const viewSelfType = ll.import("HologramLib", "viewSelfType");
viewSelfType("Steve", "minecraft:zombie");

Display yourself with someone else's skin¶

viewSelfSkin(playerName, skinOfPlayer)

Parameters:
playerName : String
the player's name
skinOfPlayer : String
the name of the online player the skin comes from
Return value: true = it was registered; false = the player is offline
Return type: Boolean

Example:

const viewSelfSkin = ll.import("HologramLib", "viewSelfSkin");
viewSelfSkin("Steve", "Alex");   // Steve takes on Alex's look

Change the nametag above your own head¶

viewSelfName(playerName, nametag, alwaysShow)

Parameters:
playerName : String
the player's name
nametag : String
the new name (supports § colour codes); an empty string = clear the name
alwaysShow : Boolean
true = the nametag is always shown
Return value: true = it was registered; false = the player is offline
Return type: Boolean

Example:

const viewSelfName = ll.import("HologramLib", "viewSelfName");
viewSelfName("Steve", "§cCaptain", true);

Hide yourself from everyone¶

viewSelfHide(playerName, hidden)

Parameters:
playerName : String
the player's name
hidden : Boolean
true = nobody else can see you; false = visible again (equal to withdrawing this override)
Return value: true = it was registered; false = the player is offline
Return type: Boolean

Example:

const viewSelfHide = ll.import("HologramLib", "viewSelfHide");
viewSelfHide("Steve", true);    // stealth mode: nobody can see Steve
viewSelfHide("Steve", false);   // reappear

Per-field and per-id operations¶

When you cannot get someone else's uniqueId, use viewTargetType; to clear every override on one entity in a single call, use viewClearId.

Make all players see it as that type¶

viewTargetType(entityUniqueId, type)

Parameters:
entityUniqueId : Integer
the entity's unique id
type : String
an entity type name, such as "minecraft:cow"
Return value: true = it was registered; false = type is empty and there is no override to withdraw
Return type: Boolean

Example:

const viewTargetType = ll.import("HologramLib", "viewTargetType");
viewTargetType(12345, "minecraft:sheep");   // everyone sees a sheep

Withdraw every override on this entity¶

viewClearId(entityUniqueId)

Parameters:
entityUniqueId : Integer
the entity's unique id
Return value: true = it was withdrawn; false = there is no such override
Return type: Boolean

Example:

const viewClearId = ll.import("HologramLib", "viewClearId");
viewClearId(12345);

Queries and diagnostics¶

Drain the "entity just spawned" queue (1.30.0 / 26.51.4)¶

viewPollSpawnEvents()

Parameters: none
Returns: an array of strings, one per entity that just spawned; reading empties the queue (same drain semantics as ghost* / containerPollClicks)
dropped items: drop|uid|dim|x|y|z|
everything else: actor|uid|dim|x|y|z|identifier
Return type: Array<String>
Notes: the event is recorded inside the outbound hook (once per entity), so scripts no longer need a periodic 0.5–1 s scan to find "whatever just spawned" — one tick is enough. Typical use: take over a dropped item with itemDisplayEmitForEntity(player, uid, ...) the moment it spawns; apply disguise rules the moment a mob spawns. The queue is capped (512 entries); a stalled script loses the oldest ones.

Example:

const pollSpawn = ll.import("HologramLib", "viewPollSpawnEvents");
const attach    = ll.import("HologramLib", "itemDisplayEmitForEntity");

function onTick() {
    for (const ev of pollSpawn()) {
        const [kind, uid, dim, x, y, z, identifier] = ev.split("|");
        if (kind === "drop") attach(Number(uid), "-0.4", "0", "0", "0.375", 180, 2, "", true);
    }
}

Look up a player's uniqueId by name¶

viewUniqueIdOf(playerName)

Parameters:
playerName : String
the player's name
Return value: that player entity's uniqueId; -1 = offline (the uniqueId itself may be negative, so only -1 counts as the test — do not write < 0)
Return type: Integer

Example:

const viewUniqueIdOf = ll.import("HologramLib", "viewUniqueIdOf");
const uid = viewUniqueIdOf("Alex");
if (uid !== -1) logger.info(`Alex's uniqueId = ${uid}`);

Check how many overrides a player carries¶

viewDescribe(playerName)

Parameters:
playerName : String
the player's name
Return value: a summary starting with entities=N blocks=N, followed by several hook counters (read it when working out whether an override took effect)
Return type: String

Example:

const viewDescribe = ll.import("HologramLib", "viewDescribe");
logger.info(viewDescribe("Steve"));

Echo a string back verbatim¶

viewEcho(text)

Parameters:
text : String
any string
Return value: looks like len=12 hex=7479... text=[...]; hex is the first 16 bytes at most
Return type: String

Example:

const viewEcho = ll.import("HologramLib", "viewEcho");
logger.info(viewEcho("type=minecraft:cow"));   // first confirm this string was not truncated or mangled

Verify the metadata a spec folds into, offline¶

viewMetaProbe(spec)

Parameters:
spec : String
the override content (the same as viewEntity)
Return value: looks like items=N bytes=N hex=...; items=0 plan=empty when the spec has no effective item
Return type: String

Example:

const viewMetaProbe = ll.import("HologramLib", "viewMetaProbe");
logger.info(viewMetaProbe("type=minecraft:sheep;color=5"));   // see what this string actually sends

Check whether dropped-item spawn packets are intercepted¶

viewItemSpawnHooked()

Return value: always true in this version (re-typing / hiding a dropped item in one shot); an older library does not have this function name (ll.hasExported judges it false) → treat it as unsupported, and the script has to re-apply the override periodically
Return type: Boolean

Example:

const viewItemSpawnHooked = ll.import("HologramLib", "viewItemSpawnHooked");
if (viewItemSpawnHooked()) logger.info("dropped-item overrides land in one shot, no periodic re-applying needed");

Sensing (sensing*)¶

The data source is the input method the client reports every tick, and the library keeps it in memory. No events and no polling — query it directly when you need it.

Look up the player's current device¶

sensingDeviceOf(playerName)

Parameters:
playerName : String
the player's name
Return value: keyboardMouse / touch / gamepad / motionController / unknown (unknown when the player is offline or has not reported input yet)
Return type: String

Example:

const sensingDeviceOf = ll.import("HologramLib", "sensingDeviceOf");
logger.info(`Steve's device: ${sensingDeviceOf("Steve")}`);

Check whether the player is on touch¶

sensingIsTouch(playerName)

Parameters:
playerName : String
the player's name
Return value: true = touch; false = not touch, or the player is offline
Return type: Boolean

Example:

const sensingIsTouch = ll.import("HologramLib", "sensingIsTouch");
const containerOpen  = ll.import("HologramLib", "containerOpen");
const tradeOpen      = ll.import("HologramLib", "tradeOpen");

// touch gets the container list (a click always sends packets), keyboard-mouse gets the trade menu
if (sensingIsTouch("Steve")) containerOpen("Steve", "§8Quest list", 3);
else tradeOpen("Steve", "entity.villager.butcher", 1, 0, false, "");

Get the numeric device code¶

sensingDeviceCode(playerName)

Parameters:
playerName : String
the player's name
Return value: 0 = Unknown 1 = keyboard-mouse 2 = touch 3 = gamepad 4 = motion
Return type: Integer

Example:

const sensingDeviceCode = ll.import("HologramLib", "sensingDeviceCode");
logger.info(`device code: ${sensingDeviceCode("Steve")}`);

Things to watch out for¶

It only changes the client view: the server-side world, the save, collision and what other players see all stay as they were. When a player is displayed as a cow, their id has not changed — hitting them is hitting them in person, and damage and drops are settled against the real thing.
Overrides live only in memory: a server restart loses them. An override recorded by player name still applies after that player rejoins (it is applied automatically when the entity spawns again, and blocks are re-sent automatically as chunks are delivered).
Your own client does not take part in overrides of your own entity: re-typing and hiding are for other people to see (otherwise your own client would break); only the skin-swap family (viewSelfSkin / as=) includes the player themself.
You can set an override before the entity has even spawned, and the library applies it when it spawns; conversely, an entity or block that was never going to be sent to this player (out of view, and so on) does not appear out of thin air because of an override.
On withdrawal, entities that are too far away (> 64 blocks) or already gone are not rebuilt — the client did not have them anyway, so wait for their next spawn.
Per-player glowing / invisibility cannot be done: Bedrock invisibility is an effect rather than an appearance, and this version of the API has neither item. Per-player entity scaling uses scale= (0.0625~10); do not mix it up with the skin= tier's model scaling.
sensing* needs no polling: after a device change the very next input packet updates it, and it is cleared the moment the player goes offline.
Only the interface domains (container / dialogue / trade) have events that need polling; see Interfaces & containers.

Domain guide: View override & sensing (what it can and cannot do, per-player isolation and the restore rules)
Fake player entities: Fake-player NPCs (the skin registry is where skin= comes from)
The full C++ side: C++ API reference

View override & sensing · let one player see something different / work out what device they use¶

Quick start¶

The spec string¶

Main entry points¶

Override an entity as one player sees it¶

Override a block as one player sees it¶

Withdraw one entity's override¶

Withdraw one block's override¶

Withdraw every override for one player¶

The "self" family¶

Put an override on yourself¶

Withdraw your own override¶

Make yourself look like another mob to everyone¶

Display yourself with someone else's skin¶

Change the nametag above your own head¶

Hide yourself from everyone¶

Per-field and per-id operations¶

Make all players see it as that type¶

Withdraw every override on this entity¶

Queries and diagnostics¶

Drain the "entity just spawned" queue (1.30.0 / 26.51.4)¶

Look up a player's uniqueId by name¶

Check how many overrides a player carries¶

Echo a string back verbatim¶

Verify the metadata a spec folds into, offline¶

Check whether dropped-item spawn packets are intercepted¶

Sensing (sensing*)¶

Look up the player's current device¶

Check whether the player is on touch¶

Get the numeric device code¶

Things to watch out for¶

Related¶