I need help with After Effects Badly

V

VikinGSteeeZ

New member
Hey, I've been working with after effects and I'm having trouble with rotoscoping. I've read numerous tutorials all that have not helped. I have a school project I need to get done involving this and I'm getting pretty frustrated, haha.

Can anyone tell me how to layer two videos in order so that when you make a mask the other shows up. An example would be that effect of someone being hit by a car. If someone could use that as an example of how you would be able to layer those two videos and masking part too that would be help so much. Thanks, see ya
 
Set up a comp at the size and framerate you need.

Add the footage you want on the comp at the bottom (ie say the car)

Add the footage you want on the top (say the guy walking)

Go to the pen tool (on the toolbar (it looks like the nib of a fountain pen)

Draw a spline around your guy (use as few points as possible while trading off against accuracy). He should now be "cut out"

Go to the "guy walking"layer in the comp (at the timeline) - open it out - you should see a yellow "mask" layer - open this out by clicking the arrow next to it.

click the little "clock" symbol next to the mask shape layer.

Drag your timeline to, say, the end of his walk. Your guy should move but the mask does'nt.

Grab the arrow tool (top left)

Double click on any point in your mask in the window. It should be highlighted.

Pull this point so it follows your guy. (keep the points relative ie. if the point was on his ankle frame 1 then keep it on his ankle at frame 50 - geddit?). You will now see a "keyframe" on the timeline under the mask layer.

Do this for the other points. (ie drag the points around him so you cut him out using the mask)

drag your timeline to, say, halfway through your animation.

The mask should auto animate but maybe it's a little off and needs a little help - pull the points the same way (double click a point - pull it to where it should be - ankle to ankle etc). Do this until he's accurately cut out again. Another keyframe has appeared under the mask layer.

Then drag to another halfway point between the keyframes - do the same - pull the points until he is cut out

keep doing this - refining between the keyframes - it should be getting more accurate all the time. You should end up with quite a lot of mask animation keyframes if you want it accurate.

You might also want to adjust "mask feather" (on the timeline) so its not too sharp and cookie cutter. 2 pixels is generally helpful.

Thats kind of it really - quite slow and, unfortunately, laborious. :zombie_smiley:

But hopefully the results are worth it :)

Good luck with it.
 
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