Linksets

An object is a linkset: one root prim plus any child prims, moving and rezzing as a unit. Each prim has a link number. The root is 1 when there are several prims, and 0 in a single-prim object. Seated avatars are added after the prims.

Most prim functions have a Link variant that works on any prim by link number, so one script can control the whole object. What a single prim looks like is covered by Prims.

Concepts

Every prim has a link number; the object has a number of prims (including seated avatars) and a prim count
- Special link constants address the root, this prim, all prims, all others or all children
- Names and keys help find a prim by role instead of by number, because numbers change when the object is relinked
Linking and unlinking need PERMISSION_CHANGE_LINKS from the owner
- The changed event reports CHANGED_LINK
One script can set or read many properties of any prim, or several prims, in one call
- Scripts in different prims talk with link messages
The object as a whole has a root position, a bounding box, a mass and an owner, and can be scaled as a unit
- Details of other objects are read by key
Objects in inventory can be rezzed with a position, velocity and parameters
- llRezObjectWithParams sets many properties at rez time
- The child receives the start parameter in on_rez
- Objects can delete themselves or derez others they own

Functions and events

`integer`	`llGetLinkNumber()`
`integer`	`llGetNumberOfPrims()`
`string`	`llGetLinkName(integer link)`
`key`	`llGetLinkKey(integer link)`
`void`	`llCreateLink(key target, integer parent)`
`void`	`llBreakLink(integer link)`
`void`	`llSetLinkPrimitiveParamsFast(integer link, list rules)`
`list`	`llGetLinkPrimitiveParams(integer link, list params)`
`void`	`llMessageLinked(integer link, integer num, string str, key id)`
`key`	`llRezObjectWithParams(string item, list options)`
`event`	`on_rez(integer start_param)`
`event`	`changed(integer changes)`

Rezzing

Rez objects from inventory, pass them a start parameter or string, and derez them later.

Scripting Details

Link numbers functions

`integer`	`llGetLinkNumber()` Returns the integer link number of the prim containing the script (0 for unlinked, 1 for the root, and 2+ for children).
`integer`	`llGetNumberOfPrims()` Returns an integer representing the total number of prims and seated avatars in the linkset containing the script.
`integer`	`llGetObjectPrimCount(key prim)` Returns an integer representing the total number of prims in the object containing the specified prim.
`string`	`llGetLinkName(integer link)` Returns a string containing the name of the linked prim specified by link.
`key`	`llGetLinkKey(integer link)` Returns the key (UUID) of the linked prim or avatar specified by link.
`integer`	`llGetLinkNumberOfSides(integer link)` Returns an integer representing the number of sides (faces) of the linked prim specified by link.
`integer`	`LINK_ROOT = 1` Refers to the root prim of the linkset.
`integer`	`LINK_SET = -1` Refers to every prim in the linkset.
`integer`	`LINK_THIS = -4` Refers specifically to the single prim containing the running script.
`integer`	`LINK_ALL_OTHERS = -2` Refers to every other prim in the linkset, excluding the prim containing the script.
`integer`	`LINK_ALL_CHILDREN = -3` Refers to all child prims in the linkset (every prim except the root).

Linking and unlinking

`void`	`llCreateLink(key target, integer parent)` Attempts to link the object containing the script with target. Requires the PERMISSION_CHANGE_LINKS runtime permission.
`void`	`llBreakLink(integer link)` Delinks the prim specified by the link number link. Requires the PERMISSION_CHANGE_LINKS runtime permission.
`void`	`llBreakAllLinks()` Delinks all prims in the linkset. Requires the PERMISSION_CHANGE_LINKS runtime permission, which must be requested and granted by the owner.
`event`	`changed(integer changes)` Triggered when various properties of the object change. The parameter changes is a bitfield of CHANGED_* flags.
`integer`	`CHANGED_LINK = 0x20` Number of prims making up the object or avatars seated on it has changed. Also occurs when duplicating a linked object or when a prim changes type or shape. Does not trigger on attach/detach, sit/unsit in attachments, or single prim duplication.
`integer`	`PERMISSION_CHANGE_LINKS = 0x00080` Runtime permission that allows the script to successfully create, break, or modify links to other objects using llCreateLink, llBreakLink, or llBreakAllLinks.

Controlling every prim

`void`	`llSetLinkPrimitiveParamsFast(integer link, list rules)` Sets primitive parameters for the linked prim link according to rules with no built-in script sleep delay.
`list`	`llGetLinkPrimitiveParams(integer link, list params)` Returns a list of primitive parameters requested in params for the linked prim specified by link (equivalent to llGetPrimitiveParams).
`void`	`llSetLinkColor(integer link, vector color, integer face)` Sets the Blinn-Phong diffuse RGB color of face on the linked prim link.
`void`	`llSetLinkAlpha(integer link, float alpha, integer face)` Sets the Blinn-Phong alpha (transparency) of face on the linked prim link.
`void`	`llSetLinkTexture(integer link, string texture, integer face)` Applies texture (UUID or inventory name) to face of the linked prim link.
`void`	`llMessageLinked(integer link, integer num, string str, key id)` Triggers a link_message event, sending num, str, and id to the scripts in the prim(s) specified by link to allow scripts within the same object to communicate.

The object as a whole functions

`vector`	`llGetRootPosition()` Returns a vector representing the position (in region coordinates) of the root prim of the linkset containing the script.
`rotation`	`llGetRootRotation()` Returns a rotation representing the orientation (relative to the region) of the root prim of the linkset containing the script.
`list`	`llGetBoundingBox(key object)` Returns the bounding box of object (including any linked prims) relative to its root prim in local coordinates, formatted as [ (vector) min_corner, (vector) max_corner ].
`vector`	`llGetGeometricCenter()` Returns a vector representing the geometric center of the object relative to its root prim.
`vector`	`llGetCenterOfMass()` Returns the vector position (in region coordinates) of the center of mass. Returns the individual child prim's center of mass if called from a child, or the entire linkset's center of mass if called from the root.
`float`	`llGetObjectMass(key id)` Returns a float representing the mass of the avatar or object specified by id.
`list`	`llGetObjectDetails(key id, list params)` Returns a list containing the requested parameters of the specified avatar or object id, retrieved in the order requested by params.
`key`	`llGetOwnerKey(key id)` Returns the key (UUID) of the owner of the prim specified by id.
`key`	`llGetCreator()` Returns the key (UUID) of the prim's original creator.
`integer`	`llScaleByFactor(float scaling_factor)` Attempts to uniformly resize the entire object by scaling_factor, maintaining size-position ratios of the prims. Fails if the linkset is physical, a pathfinding character, in keyframed motion, would exceed prim scale/linkability limits, or would overflow parcel capacity.
`float`	`llGetMaxScaleFactor()` Returns a float representing the maximum scale factor that can be applied to the object via llScaleByFactor without violating size or linkability limits.
`float`	`llGetMinScaleFactor()` Returns a float representing the minimum scale factor that can be applied to the object via llScaleByFactor without violating size limits.

Rezzing objects functions

`key`	`llRezObjectWithParams(string item, list options)` Instantiates the named inventory object (defaulting to the rezzing prim's position unless REZ_POS is specified) using the initial set of parameters specified in options. Returns the key of the rezzed object, or a blank key on failure.
`void`	`llRezObject(string item, vector pos, vector vel, rotation rot, integer start_param)` Instantiates the named inventory object with the bounding box centered at pos with velocity vel and rotation rot, passing param as the on_rez start parameter. The vel parameter is ignored if the rezzed object is non-physical.
`void`	`llRezAtRoot(string item, vector pos, vector vel, rotation rot, integer start_param)` Instantiates the named inventory object with the root prim at pos with velocity vel and rotation rot, passing start_param as the on_rez start parameter. The vel parameter is ignored if the rezzed object is non-physical.
`event`	`object_rez(key id)` Triggered when this object successfully rezzes another object from its inventory. Passes the key (UUID) id of the newly rezzed object.
`event`	`on_rez(integer start_param)` Triggered when the object is rezzed into the world (by a script or user). Passes start_param from the rezzing call (or 0 if rezzed from inventory). Also triggers on attachments during login or when attached from inventory.
`integer`	`llGetStartParameter()` Returns an integer representing the start/rez parameter passed to the object on creation (returns 0 if rezzed by an agent).
`string`	`llGetStartString()` Returns the initialization string passed to the object's root prim on rez with llRezObjectWithParams (via REZ_PARAM_STRING; returns an empty string if rezzed by an agent).
`void`	`llDie()` Deletes the entire object containing the script (the object does not go to inventory). Use llBreakLink first to delete only a single prim.
`integer`	`llDerezObject(key id, integer flags)` Derezzes (deletes or returns) a targeted object in the region previously rezzed by a script in this linkset, returning TRUE on success or FALSE on failure.
`void`	`llGodLikeRezObject(key id, vector pos)` Rezzes an object directly from a UUID specified by id at the position pos, provided the owner has the god-bit set.

Additional

Link functions take a link number or a link constant (some take only one link)
llGetObjectDetails — OBJECT_* details of any object by key
llRezObjectWithParams — REZ_* parameters and flags
llDerezObject — derez modes
- DEREZ_DIE — immediately delete (kill) the object

Link numbers

Constant groups Link 2 Links 5

The object as a whole

Constant groups ObjectDetailsParam 56

Rezzing objects

Constant groups RezParam 13 RezFlag 8 DerezMode 3