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Breakdown Explanation of Matte
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Well, I think you may be talking about 2 different things. If you are manually putting in Keyframes, then just engage the ‘Mask Shape’ parameter’s stopwatch to start keyframing using whatever method you wish. AE will interpolate for you like any other program.
But if you are not keyframing but using a tracker instead, That’s where you will need to apply the tracker data to the layer the mask is a part of. As opposed to applying that data to the mask itself, much less any individual point.
Shake IS excellent but I wouldn’t call it inexpensive at around $3000. I have never used it, but I heard Sihlouette is the shennanigans. I personally used to use Commotion and Shake (left for dead by Pinnacle) for roto and tracking.
Chris Smith
https://www.sugarfilmproduction.com -
Chris i said shake was a “fully expensive compositing program”. Ok so lets say i have a mattepainting and i take out my background sky. If the camera was moving i would need to use AE’s motion tracker and then aply the matte painting correct?
But Chris back to roto. My main question is that is there any other way to roto in AE than to do it manually frame by frame? I make my mask around my body lets say. I have to move to the very next frame and shift the mask to keep it around my body. IS there any way the computer would give it a go to try to track my mask around my subject automatically? Interpolation? THanks again guys -
No. To do that you need to use a (the) tracker. But I’m saying that AE’s tracker will not use it’s tracking data on any of the mask points or the mask itself. But you can apply it to the layer the mask sits on. So the net result is that the mask as a whole will move on the X&Y according to whatever point you tracked.
Some compositors will allow you to assign tracking points to each mask point so that it will reshape the mask depending on what the tracker can track.
There simply is no completely automated way of rotoing complex objects. Trackers help, but still need a lot of futzing with. In my experience, not worth tracking individual points.
But I do think having a tracker – let’s say track a point on someone’s hand – making a mask shape move generally with the hand. But Still use the keyframe techniques Steve and I argued about above to actually reshape the mask for the hand 🙂
So when you are using interpolation keyframing, You are only changing the local shape to comply with the hand while the tracker moves the overall X&Y of the mask to follow the hand. This is generally how I roto and it can be pretty fast (relatively speaking).
Chris Smith
https://www.sugarfilmproduction.com -
Chris you’ve been a create help my man. I know have a pretty clear understanding after this post. I would say my only question left is what do you mean interpolation keyframes? What is interpolation?
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Actually guys, a script has been written over at AE Enhancers that acually DOES let you track individual mask points. I’ve tried it and it actually works. Here’s the link.
https://www.aenhancers.com/viewtopic.php?t=329
Sean Cusson
Q media design
sean@qmediadesign.ca -
When you set a key at say frame 1 and a key at frame 10. AE will interpolate values between those two keyframes. So frames 2 – 9 are values between what the two bookmark keyframes are. Just like original cel animation. An animator would draw Mickey Mouse in key poses (or keyframes) every 10 frames or so and an underling will do the work of drawing in between frames of Mickey so he appears to move from one key frame to the other.
To draw those inbetween frames, the underling needs to “interpolate” thedrawings in his mind. So that the movement natuarlly moves from one key to another.
So when you set any two keyframes in AE that are more than a frame apart, AE will interpolate the motion (or parameter change of any sort) for you. That’s what I was saying you should do with roto. Let AE interpolate movement as much as possible between keys because it will do it perfectly smooth. If you truly reshaped your roto mask on every frame, then you will most likely get “Roto Chatter”
Roto chatter is when you go frame by frame redrawing or reshaping a mask, you think you are doing it well, but due to being human you make tiny errors or differences on each frame. These differences only show up when you play back the footage at full speed. The edges will chatter. So the challenge in roto is to use as little keyframes as necessary and let AE interpolate between them for a smooth result.
Chris Smith
https://www.sugarfilmproduction.com -
Chris Smith you are the man. I love the fast and thorough responses. Could you point me in the right direction as far as motion tracking. I have footage where i basically pan across a field. I want to take out the sky and put in a matte painting. How would i go about letting this background pic move with the motion?
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Ok So i set a mask around my head moving from left to right. Set a keyframe at frame 1 and then a keyframe after 5 seconds. With the mask and layer selected i went to animation-keyframe interpolation. Not to sure on what settings are good to set so i stuck with what was set and i dont see any difference in my mask at all. ?
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You don’t need to change anything on the interpolation options unless you want to change the type. Like mentioned in a previous message above did you engage the ‘Mask Shape’ parameter? If you don’t not a thing will move.
What you are doing with the matte painting, I do all the time. It’s pretty simple. Although I don’t do that kind of thing in AE so you’ll have to interpret it for how you want to work:
Basically use a linear keyer or hand drawn mask (or most commonly a combination of both) to create a matte that will define the limits of where your painting shows. Then Open the tracker and track a suitable point. There are many ways to use the tracking data. My personal fave (although I track in another program and paste in keys if I use AE). Is to parent the mask layer to a null layer that has the tracking data on it. That way the mask will move with the tracker, but you can grab the layer or mask and repo it easily and it will still ride along.
You should really do yourself a favor and check out these books (After reading your AE manual):
“Creating motion Graphics” and “After Effects in Production” by Trish and Chris Meyer.
They are essentials.
Have fun.
Chris Smith
https://www.sugarfilmproduction.com -
I have creating motion graphics volume 1 meyer. I want to get volume 2 and read them together. Does volume 1 explain motion tracking in AE at all?
What I did was i duplicated my video and made an add mask around my head then used the keyframe interpolation. Im pretty sure I had the mask shape keyframe clicked but still nothing.
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