Not rocket science, just a copy of GameObjectIsNull with the GO switched to Object.
namespace HutongGames.PlayMaker.Actions
{
[ActionCategory(ActionCategory.Logic)]
[Tooltip("Tests if an Object Variable has a null value.")]
public class ObjectIsNull : FsmStateAction
{
[RequiredField]
[UIHint(UIHint.Variable)]
public FsmObject theObject;
public FsmEvent isNull;
public FsmEvent isNotNull;
[UIHint(UIHint.Variable)]
public FsmBool storeResult;
public bool everyFrame;
public override void Reset()
{
theObject = null;
isNull = null;
isNotNull = null;
storeResult = null;
everyFrame = false;
}
public override void OnEnter()
{
DoIsObjectNull();
if (!everyFrame)
Finish();
}
public override void OnUpdate()
{
DoIsObjectNull();
}
void DoIsObjectNull()
{
bool oIsNull = theObject == null;
if (storeResult != null)
storeResult.Value = oIsNull;
Fsm.Event(oIsNull ? isNull : isNotNull);
}
}
}