Overview

AVsitter2 has been ported to OpenSim, but there are still issues. In particular the prop plugin does not keep rotation on rezzed objects that are aimed to be attached, as depicted in this AVsitter issue. AVsitter developers stated (in purpose) that's it's not related to AVsitter, but an OpenSim bug, and the issue has been reported to OpenSim mantis. Unfortunately, this bug is opened since 2018 and still in the new state.

So how can users do? Well, doing a fix on AVsitter to compensate OpenSim bug. That's what this project is about.

For users

The plugin works exactly the same than the original one, just replace [AV]object with [AV]osobject inside props, and replace [AV]prop with [AV]osprop in the main sitting object. Just check that the rotation of the object is correctly set in the PROP1 line.

For interested developers

The workaround is pretty simple. As the rotation is stored in the AVpos notecard with the PROP1 line, we can forward it to the rezzed object in the [AV]prop script:

if (sitter_key != NULL_KEY && llList2String(data, 0) == "REZ" && llList2Integer(prop_types, prop_index) == 1)
{
    // typhfix: add rotation to the ATTACHTO command
    vector rot = llList2Vector(prop_rotations, prop_index);
    llSay(comm_channel, "ATTACHTO|" + (string)sitter_key + "|" + (string)id + "|" + (string)rot);
}

On the other side, in the [AV]object script, we keep storage for received rotation in the ATTACHTO command:

vector prop_rotation;   // typhfix: added to store rotation

else if (command == "ATTACHTO" && prop_type == 1 && (key)llList2String(data, 2) == llGetKey())
{
    if (llGetAgentSize((key)llList2String(data, 1)) == ZERO_VECTOR)
    {
        llSay(comm_channel, "DEREZ|" + (string)prop_id);
        // typhfix: prevent an error on OpenSim 0.8.2 console
        llSleep(0.5);
        llDie();
    }
    else
    {
        // typhfix: store rotation from the message
        prop_rotation = (vector)llList2String(data, 3);
        llRequestPermissions(llList2Key(data, 1), PERMISSION_ATTACH);
    }
}

And during permission handling, if the rotation was given, apply it:

run_time_permissions(integer permissions)
{
    if (permissions & PERMISSION_ATTACH)
    {
        if (llGetAttached())
        {
            llDetachFromAvatar();
        }
        else
        {
            llAttachToAvatarTemp(prop_point);
            // typhfix: apply stored rotation
            if (ZERO_VECTOR != prop_rotation) {
                llSetLocalRot(llEuler2Rot(prop_rotation * DEG_TO_RAD));
            }
        }
    }
    else
    {
        llSay(comm_channel, "DEREZ|" + (string)prop_id);
        llDie();
    }
}