I'm still struggling with Offset. I've laboriously plodded through 100's of scenarios to get a work flow that doesn't cause my emitters to mysteriously disappear or to have them step to places they shouldn't be!
(The conclusion generally is that I can't see any reason why the Offset point can't be moved and treated exactly the same as an emitter with the exception that it has no graph, is always default at centre stage and has the break option.)
To set the scene, I want to track a background but don't want the emitter to appear until (say) frame 6. Simple enough requirement. But it's impossible to copy the exact workflow from the help pages as that doesn't exactly fit the situation I want - I could track painfully through the scenarios I have tried it but there seems no solution and if the answer to the next question is YES, it will make the workflow (almost) painless and useable.
The main pain is that when you start a NEW screen after invoking PI you CANNOT manipulate the Offset, you have to add an emitter first. This seems weird - surely what you want to do is to track your moving background first to get that chore out of the way - then add emitters as you want later?
I have discovered that if you have a project which has emitters on it, then select Offset, then select NEW - Voila!! You are in Offset mode on a New project without first having had to load an emitter. Now, provided that you click on frame 1 first, the Offset command behaves exactly as you would expect with no disappearing emitters. Now you can track your animation then add emitters as and when and the tracking is automatic - as you would expect! OK I hear you say what's wrong with adding that first emitter? What is wrong is that it extends the workflow pointlessly and often 'disappears' implying a possible corruption. It is easy to simply delete the initial emitter after it disappears but that also makes me worry about corrupted files.
So - if I do the Offset/New trick am I going to corrupt anything?
Alternatively, if anyone has a workflow that legally fits my scenario I love to see it!
I'd really love to see a specific example of the footage you're having trouble with.
Yes, you need to add an emitter before Offset becomes available, but if that first emitter is just a "garbage" emitter, what does it matter what happens to it?
It still concerns me that you say it "disappears" -- as that should never happen if you're using "break" correctly.
You've worked through the simple example in the pI3 docs on Layer Offset to make sure you understand how to use it, right? You only use "break" when you need to "reset" the offset to a new "tracking point" -- if the point you were tracking is no longer visible.