0zin docking

set localport to ship:controlpart.
set sep to 50.
set sl to 0.
lock offset to v(0,0,0).
if target:istype("Vessel") set tVes to target.
else set tVes to target:ship.
set fpid to pidloop(3,0.01,0.1,-1,1).
set tpid to pidloop(fpid:kp,fpid:ki,fpid:kd,-1,1).
set spid to pidloop(fpid:kp,fpid:ki,fpid:kd,-1,1).

function rv {
    set rel_v to velocity:orbit - tVes:velocity:orbit.
    if target:istype("Vessel") set fa to target:facing.
    else set fa to target:portfacing.
    set wv_pos to (target:position + offset + fa:vector * sep) - localport:position.
    set wanted_v to wv_pos:normalized * min(sl , (wv_pos:mag * 0.25)^0.5).
    set ve to wanted_v - rel_v.
}

set dock to true.
when true then {
    rv().
    set ship:control:translation to v(-spid:update(time:seconds, vdot(facing:starvector,ve)),-tpid:update(time:seconds,vdot(facing:topvector,ve)),-fpid:update(time:seconds,vdot(facing:vector,ve))).
    return dock.
}
lock steering to lookdirup(-target:facing:vector, target:facing:topvector).