^: I'm not sure I understand your question. I am using Animated Pictures (AKA: Custom Objects) to "replace" standard object graphics. Is this something XLua can do directly?
If you try to send an instruction to a CO from a "behavior" then the instruction will be sent to every CO on screen. To make it work you'll need to add CO's to a group, I used "friends". Then you'll need to add a unique identifier to each Animated Object/CO pair, I used "friends" count-1. When you pass instructions to COs you need to do it in the Main event area of the "Gameplay" frame. Match identifiers of the animated objects and COs by looping through the "friends" group. There will be 3 conditions on every event in addition to what you're checking for. The following is pseudo-code because I don't remember exactly:
on loop "sync"
Friend.identity = loop "sync".iteration
ActiveObject.identity = loop "sync".iteration
Note: Make sure you pass instructions to COs using the group's column.
Or at least, that's how I got it to work. I'd only been working with MMF2 for 3 days when I figured this part out so it's likely there is a better solution. If there isn't then MMF2 is ridiculous.
Edit: 02August2011: There is a better solution for what I'm describing above. I'm going to put it here for the benefit of future readers. First of all, I was explaining how I got 2 separate objects to interact with each other while not affecting other objects of the same types. It really all comes down to giving the 2 objects the same unique identity. Store this value in them in the same event they are created in. This way it will only be stored in the newly created objects, rather than all objects of the same type. Afterwards, when you want to make an adjustment to one object based on the state of the other. First create a loop that will iterate through the possible IDs. Then create an event that includes filters for the loop itself (On Loop), comparisons between both objects' IDs and the loop value, and whatever conditions you want to act on. What is extremely important here is how you make the comparisons between both objects' IDs and the loop value. The objects must appear as the left conditionals in both comparisons. Right conditionals do not filter the field of similar objects. If you do it correctly, then any actions taken will only affect the two objects in the pair. It even works from within behaviors despite things being passed by reference.