[Stuart Elith]

The other way to do this is to have the mask on a separate layer, such as a solid, and then use it as a track matte for the picture layer. Then you have independent control of the two layers, but can still parent them or whatever if you do want to.
It does mean an extra layer, but sometimes it’s easier.

[Stuart Elith]

AE 8 is CS3, and AE9 is CS4. AE7 is the equivalent of CS2 but they didn’t call it that, I think.

I don’t know exactly about which versions have motion tracking… i’m sure you could google for this info, the multiple versions thing (professional vs standard) seems confusing to me (i just know the pro version has everything!).

if you’re using AE quite a bit, it may be worth considering upgrading anyway… i haven’t got CS4 yet but CS3 does have some nice additions, such as the puppet tool and various other stuff.

[Stuart Elith]

Hmmm, interesting.
I just checked, and I can indeed rest my time on ANY keyframe and it will work, adjusting by scrubbing a value, or moving it around in the comp window with my arrow, or even nudging with arrow keys.

I am on CS3 though so perhaps they have changed it (seems like it would be a step backwards in my opinion). Also on a Mac, though you wouldn’t expect that to matter either.

[Stuart Elith]

There’s a difference matte in AE as well, the problem is that, indeed, it basically is useless.
I’ve only tried it a few times but it tends to result in crusty edges and unwanted transparency due to tiny differences, compression, noise etc.

This other current thread
https://forums.creativecow.net/thread/2/953785
has a few youtube examples of people playing around with it, and those demonstrate its shortcomings quite well.

I think the general consensus is that it’s not worth the bother.

[Stuart Elith]

Just FYI, it should work as long as your current time is on ANY of the keyframes. 🙂

[Stuart Elith]

Sounds to me like it’s a problem of keyframe interpolation… often happens to me especially with camera stuff.
you can right click on a keyframe and choose Keyframe Interpolation, where you will be presented with a bunch of options. Try swapping from Auto Bezier or Continuous Bezier to Linear, and see what that does.

[Stuart Elith]

Yeah, i was thinking along these lines as well…
if you take your entire comp and precomp it, then you can play around with the timing and insert/retime stuff as needed. Only works if you don’t need to deal with specific elements while other stuff keeps going, but may be applicable.

[Stuart Elith]

I think there are a few things at play here… firstly, if your track isn’t DEAD ON you will see some shifting, because the paper is so large and central on the screen, so it will be very noticeable.
You could try averaging a few different trackers to get solid tracking data (if you search for this you will find some explanations, and TrackerViz is a great script you can freely download).

In terms of the ink blot moving position, you have a few options. You can translate all the tracking data by adjusting the anchor point for the ink layer. Apply the data, then shift the anchor point and all the position keyframes will still do their thing but be offset by the difference.

[Stuart Elith]

Jamil, I’m not sure if I exactly understand what you are doing, but I think you have misunderstood Luma Mattes.

They aren’t designed to affect the luminance of a source, but the transparency (just like an alpha matte). The difference is that it’s TAKING the luminance from the top layer and using that as a mask for alpha. So you are getting transparent areas on the turtle where the pixels are darker.
They are very useful, but as you’ve found, not for actually affecting luminance.

[Stuart Elith]

You can also set the point of interest to always align with the camera… it’s under Layer > Auto-Orient. You can choose from 3 settings there when you have a camera selected.
Some prefer to work this way, others like to have the flexibility to animate both attributes. It varies for me, depending on what kind of motion I will be creating.