LlSetLinkPrimitiveParams

Set primitive parameters for linknumber based on rules. You may prefer to use llSetLinkPrimitiveParamsFast which behaves identically except does not sleep the script.

A simple script to light up a prim in a linkset when touched, and unlight the others using llSetLinkPrimitiveParams, when script is installed in the root prim of the linkset.

default
{
    touch_start(integer total_number)
    {
        // Turn off all prims
        llSetLinkPrimitiveParams(LINK_SET,[PRIM_FULLBRIGHT,ALL_SIDES,FALSE]);
        // Turn on the one that was touched
        llSetLinkPrimitiveParams(llDetectedLinkNumber(0),[PRIM_FULLBRIGHT,ALL_SIDES,TRUE]);        
    }
}

 //-- PRIM_ROTATION workaround for child prims (works in unattached objects only)
llSetLinkPrimitiveParams( linknumber, [PRIM_ROT_LOCAL, rot * llGetRootRotation()] )
 
 //-- PRIM_ROTATION workaround for child prims (works in linked objects only)
llSetLinkPrimitiveParams( linknumber, [PRIM_ROT_LOCAL, rot * llList2Rot( llGetLinkPrimitiveParams( LINK_ROOT, [PRIM_ROT_LOCAL] ), 0 )] )
 
 //-- PRIM_ROTATION workaround for child prims (works in all scenarios)
llSetLinkPrimitiveParams( linknumber, [PRIM_ROT_LOCAL, rot * llList2Rot( llGetLinkPrimitiveParams( !!llGetLinkNumber(), [PRIM_ROT_LOCAL] ), 0 )] )

Link Numbers

Each prim that makes up an object has an address, a link number. To access a specific prim in the object, the prim's link number must be known. In addition to prims having link numbers, avatars seated upon the object do as well.

• If an object consists of only one prim, and there are no avatars seated upon it, the (root) prim's link number is zero.
• However, if the object is made up of multiple prims or there is an avatar seated upon the object, the root prim's link number is one.

When an avatar sits on an object, it is added to the end of the link set and will have the largest link number. In addition to this, while an avatar is seated upon an object, the object is unable to link or unlink prims without unseating the avatars first.

Counting Prims & Avatars

There are two functions of interest when trying to find the number of prims and avatars on an object.

• llGetNumberOfPrims() - Returns the number of prims and seated avatars.
• llGetObjectPrimCount(llGetKey()) - Returns only the number of prims in the object but will return zero for attachments.

integer GetPrimCount() { //always returns only the number of prims
    if(llGetAttached())//Is it attached?
        return llGetNumberOfPrims();//returns avatars and prims but attachments can't be sat on.
    return llGetObjectPrimCount(llGetKey());//returns only prims but won't work on attachments.
}

Link Numbers

Each prim that makes up an object has an address, a link number. To access a specific prim in the object, the prim's link number must be known. In addition to prims having link numbers, avatars seated upon the object do as well.

• If an object consists of only one prim, and there are no avatars seated upon it, the (root) prim's link number is zero.
• However, if the object is made up of multiple prims or there is an avatar seated upon the object, the root prim's link number is one.

When an avatar sits on an object, it is added to the end of the link set and will have the largest link number. In addition to this, while an avatar is seated upon an object, the object is unable to link or unlink prims without unseating the avatars first.

Counting Prims & Avatars

There are two functions of interest when trying to find the number of prims and avatars on an object.

• llGetNumberOfPrims() - Returns the number of prims and seated avatars.
• llGetObjectPrimCount(llGetKey()) - Returns only the number of prims in the object but will return zero for attachments.

integer GetPrimCount() { //always returns only the number of prims
    if(llGetAttached())//Is it attached?
        return llGetNumberOfPrims();//returns avatars and prims but attachments can't be sat on.
    return llGetObjectPrimCount(llGetKey());//returns only prims but won't work on attachments.
}

PRIM_POSITION

Avatars sitting on the object can be moved with llSetLinkPrimitiveParams and PRIM_POSITION. This was originally a mis-feature but according to Andrew Linden LL has decided to support it.

Examples

The below example moves an avatar to x,y,z without moving the prim they are sitting on. If x,y,z is more than 54 meters away the call will silently fail. Remember x,y,z is in object relative coordinates just like any other linked prim in a set.

Avatars are always the last prims in the set, so llGetNumberOfPrims can be used for a single avatar sitting on a vehicle.

llSetLinkPrimitiveParams(llGetNumberOfPrims(), [PRIM_POSITION, <x,y,z>]);

Functions

Articles

All Issues

		SVC-2105	[A, C]		llSetLinkListPrimitiveParams() for setting multiple, specific linked items
		SVC-914	[A, C]		CHANGED_TEXTURE is not triggered when texture is changed via script
		SVC-93	[A, C]		llSetRot and llSetPrimitiveParams (using PRIM_ROTATION) incorrectly implemented for child prims.

Footnotes

function void llSetLinkPrimitiveParams( integer linknumber, list rules );
integer PRIM_PHYSICS_SHAPE_PRIM = 0;//Use the normal prim shape for physics
integer PRIM_PHYSICS_SHAPE_CONVEX = 2;//Use the convex hull of the prim shape for physics