Skip to content

llWorldPosToHUD

vector llWorldPosToHUD(vector world_pos)

Returns the local position that would put the origin of a HUD object directly over world_pos as viewed by the current camera.

Parameters

world_pos (vector): The world-frame position to project into HUD space

Technical Details

Return Type: vector
Energy: 10

Only works for HUD attachments
The vector’s X component will be 1.0 when world_pos is in front of camera and -1.0 when it is behind
Returns zero vector when no permissions have been granted

Examples

// llWorldPosToHUD() example
//
// Put this script on a HUD attachment (which attachment point doesn't matter).
// Touch to toggle 'tracking' on/off.
// Put an object at world_pos as reference for where the HUD should move when 'tracking'.

vector not_tracking_color = <1.0, 1.0, 1.0>; // white
vector tracking_front_color = <0.5, 0.0, 0.5>; // magenta
vector tracking_behind_color = <0.0, 0.5, 0.5>; // cyan

vector world_pos = <32,32,24>; // change this position as necessary, put a ref object here
integer tracking = FALSE;

default
{
    state_entry()
    {
        llOwnerSay("Touch HUD to toggle tracking");
        llRequestPermissions(llGetOwner(), PERMISSION_TRACK_CAMERA);
        llSetAlpha(0.5, ALL_SIDES); // make object semi transparent
        llSetColor(not_tracking_color, ALL_SIDES);
    }

    touch_start(integer total_number)
    {
        llRequestPermissions(llGetOwner(), PERMISSION_TRACK_CAMERA);
        tracking = !tracking;
        if (tracking)
        {
            llSetTimerEvent(0.01);
            llSetColor(tracking_front_color, ALL_SIDES);
        }
        else
        {
            llSetTimerEvent(0.0);
            llSetPos(<0,0,0>);
            llSetColor(not_tracking_color, ALL_SIDES);
        }
    }

    attach(key id)
    {
        if (id != NULL_KEY)
        {
            llSetPos(<0,0,0>);
            tracking = FALSE;
            llSetTimerEvent(0.0);
        }
    }

    timer()
    {
        integer attachment_point = llGetAttached();
        if (attachment_point >= ATTACH_HUD_CENTER_2 && attachment_point <= ATTACH_HUD_BOTTOM_RIGHT)
        {
            vector hud_pos = llWorldPosToHUD(world_pos);
            if (hud_pos.x > 0.0)
            {
                // world-pos is in front of camera
                llSetColor(tracking_front_color, ALL_SIDES);
            }
            else
            {
                // world_pos is behind camera
                llSetColor(tracking_behind_color, ALL_SIDES);
            }
            // update HUD position
            llSetPos(hud_pos);
        }
    }
}

See Also