I have a problem with removing an object that goes behind a another object in a moving picture.
Its the purple bag on the right side of the porch. I have looked at a lot of tutorials but none does the job.
How can I do this?
on Nov 6, 2016 at 4:22:35 pm Last Edited By Roei Tzoref on Nov 6, 2016 at 4:25:45 pm
there are a few ways to do this. all involve tracking and rotoscoping. since there is a lot of perspective it this shot, I would try using the 3D Camera tracker in AE. track the shot, find the plane you want to replace, create a target. create a solid and camera. test that it sticks.
now for creating the patch. I do this inside a precomp of the footage. freeze frame. (did it on 0:01:59:00 timecode) I create the stamp, then duplicate the footage and set the duplicate to "on transparent" (it does not work when you have one layer referencing itself...)
in my master comp set this patch precomp to 3d and shift parent it to the solid's position so it will be placed in the same perspective and position in 3d space as the solid that was perfectly placed before. now it's distorted in perspective because we placed in perspective what was already in perspective. so go to same frame where you stamped the clean part at 0:01:59:00 and add the CC POWER PIN EFFECT to stretch my stamp back to perspective (just use the pins manually to set it to frame)
now for roto. create a solid above my precomp. use masks in the areas I want and set to by my Alpha inverse matte for my precomp. create another solid for the pole to cover semi-transparent areas that show the purple bag
now your left with maybe a little color correction and adding grain.
Yes it is complex if you are relatively new to compositing. You can learn by searching the terms I used in the Ae help files (upper right corner of your Ae interface contains a search field). And follow along my workflow or similar workflows.
The workflow is tracking the shot to match the movement of the patch you are going to place instead. Read about the 3D camera tracker. The other part involves creating the patch instead - you can do this in Ae or photoshop. After you have placed the patch where it needs to be, you have to mask parts that obscure it... Good luck.