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How to make a person hold and move a picture added in post production?
Hi, next week I have to film a person grabbing and holding in front of a camera some large slides which are to be added in post production so I can put a glow effect on them, etc. I’m not sure if After Effects is the best program to do this so I am open to any suggestions. What the person does is in front of a still camera he will pickup from offscreen slides (the slides aren’t real, these are the ones being added in post), hold them in front of the camera, and move it off screen (there are four slides so he will do this four times). My first question would be what do I need to do in production, do I need to get the character to have a black or white dot on each hand and is there anything else I should be aware of? Then, how do I add the slides on in post?
I know this is a pretty big question but if anyone could give a rough guide it would be greatly appreciated!! 🙂
Many thanks,
Matt -
6 Replies
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Have your subject pick up real pieces of cardboard with large black dots in the four corners. Then use a 4 point motion track to animate your glowing cards. Put a duplicate copy of your footage above the cards and rotoscope the fingers and hands.
Follow THIS tutorial too ease some of the pains of rotoscoping.
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“Life Should Come With Backround Music”
-Brown Sugar Studios- -
When you do the motion tracking you’ll run into the problem of when the tracking points going off the screen. I’m not sure what the best solution to fixing that little hangup is in this situation. I’ve yet to do a four point motion track that does it.
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“Life Should Come With Backround Music”
-Brown Sugar Studios- -
Hi,
I’ve never used AE’s tracking function much so I can’t speak for it. In Shake, it is possible to offset a tracker point’s pattern search area so that you can track a point that is onscreen to locate the point that is going off screen. AE may have an offset function like this.
In any case I have used Shake to track panning shots of signs and TV screens as they are panned on or off screen. You set you four tracker points and then as the object approaches the edge of the frame, you offset the points that are going off screen and continue the track. I will usually set the off screen search pattern to the still on screen track points until all points are off screen. As that last points pan off screen, I usually have to manually adjust exactly where they fall.
Another thing to consider. If the actor holds the dummy card with tracking points at an angle that approaches perpendicular to the camera so that the points become harder to distinguish, you may run into serious problems trying to track them. If you can the the card reasonably flat to the camera, then the track should be much easier.
Also if you can shoot in a progressive video format, that will make your life easier. Interlaced video is no friend to trackers.
Hope this helps.
Lars
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Matt, you have cross-posted this to the Adobe site and possibly other AE forums, please do us all the courtesy of coming back and closing the threads by telling us how you solved your production issues.
Are these 35mm slides? They are very small and that will complicate everything.
You must rotoscope around the actor’s fingers if your inserted images will fill the entire frame. if they just fill the film chip inside the cardboard mount, be sure your actor does not cover any of the chip.
If you’re just filling the chip, you do not need to have tracking dots on the image because the hard edge of the slide mount is easily tracked.
Suggest you purchase any of the major AE books by Angie Taylor or the Meyer kids. They have gret chapters on motion tracking. Motion tracking is really hard. Be sure to study up on this and do some tests long before you schedule your shoot.
bogiesan
This is my standard sigfile so do not take it personally: “For crying out loud, read the freakin’ manual.”
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Like “bogiesan” said, if you can keep the actors fingers off the celluloid part of the slide you can track that and replace it, here are some tuts that should help:
Keep motion in perspective, this is what you want, If I read you right
https://studio.adobe.com/us/tips/tip.jsp?p=1&id=100241&xml=aft65cornerpin
Using the new Motion Tracker
https://studio.adobe.com/us/tips/tip.jsp?p=1&id=487&xml=aft6ttmotiontracker
Tracking obscured objects in video. This is needed when your slides run off the screen in either direction, you can keep the attach points intact, here’s a paragraph from the tut:
5. Move the search and feature regions.When the tracked object becomes obscured so that the feature region can no longer track it, stop the analyzing process. If necessary, back up a few frames, and then move the feature and search regions to the new feature. Leave the attach point in the same location by pressing Alt (Windows) or Option (Mac OS) as you drag the area of the track point between the search and feature regions, or by dragging the edge of the feature region.
The tracker might convert your track to RAW when you run off the screen, but after you make the adjustment above, you can finish the frames, then convert the “TrackType” back to Perspective Corner Pin, then Apply to finish. You can also manually adjust the corner pin in the Effect>Coner Pin (Created after you hit Apply).
https://studio.adobe.com/us/tips/tip.jsp?p=1&id=399&xml=aft6tracking
At 5 minutes into this tut, Aharon shows how to adjust a track frame by frame, “when tracking goes bad”… It’s a one point track, but the principal is the same for your 4 point track, movie here:
https://forums.creativecow.net/articles/rabinowitz_aharon/cartoon_look/CC_LiveTrace_Pt_3CD.mov
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Hi everyone,
Thanks heaps for your suggestions. I was fortunate in a lot of ways as the client pulled the idea the night before filming. However, I had everything ready to go from the suggestions above. As I am pretty new (very new actually) to After Effects I wanted a backup approach. One guy on another forum suggested that I use chroma green pieces of cardboard and key it out with the image behind. Then my method of tracking would be using Final Cut Pro and the distort tool frame by frame to each corner. This was going to be my backup method (although very painful), but then I was going to do another take with the 4 points as mentioned by yikesmikes.
Luckily I got out of it this time but I think I”ll start practicing for the next project.
Thanks again,
Matt
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