Tuesday, January 23rd, 2018

Tips for Motion Tracking with Mocha for After Effects CS4


*UPDATE: see my quick “3-minute Podcast” video showing the workflow of this technique HERE!

I’ve also included an extensive step-by-step workflow on both motion tracking and image stabilization in my new training DVD, “Learning After Effects CS4” – link to it on the right –>

After much trial and error and a lot of frustrated discussions in the developer forums, I’ve FINALLY been able to successfully get a decent track with the new workflow in After Effects CS4 using the included Mocha for AE motion tracker!

If you’re new to After Effects, this will probably not be any more intimidating than learning the rest of the workflow process, but even experienced AE producers have been tripped up by the new software. There are many steps you need to take to prepare your footage for this process to get the desired results. Merely following the step-by-step guide that comes with Mocha for AE will only confuse you more if you don’t have everything setup correctly! The footage files you use, the selections you make when importing the footage to track in Mocha, the preparation of your After Effects project and composition – all play a part in a successful track.

*Note: This isn’t a tutorial – merely a list of items to look out for when using these applications together.

• Footage files: Both the footage that you are tracking and the insert footage MUST match in size and be edited down to the exact running time that you want to use. They also MUST be the exact same frame rate if you are going to be successful at matching them up in After Effects.

• Take care when importing your footage file into Mocha to track – be sure that the frame rate that is specified when importing matches the exact same rate of your actual footage. (The default seems to be 23.976fps – most video footage and Quicktime movies you download will probably be 29.97. Computer generated animations are generally anywhere from 15fps-30fps, so be sure to check your footage ahead of time!). Also, if you change the frame rate at all, you will need to make sure that you ALSO CHANGE the frame count, as Mocha will NOT adjust the frame count automatically once you change the frame rate upon importing. You may need to get out the calculator at this point – but knowing this info ahead of time will definitely help.

You can change the Prefs in Mocha to a framerate standard that you use the most, to eliminate the need for changing it at import and having to recalculate frame counts

• Be sure that you have selected the right aspect ration before tracking. Do this by selecting the “Clip” tab on the lower right, then the “Film” tab on the lower left and chose the pull-down menu item that best matches your actual footage. Failure to select the right aspect ratio here will result in a bad, bad track-match in After Effects.

• First follow the instructions for setting up the motion tracker. If you have a clean internal edge like the screen in my movie below, then there is no need for a hold-out tracking frame – just use the outter tracker spline.

• If you are going to use the Corner Pin data then you need to apply a Surface Tracker. Turn on the grid to see the actual tracking activity, but it’s not necessary.

• Export the tracking data after you’ve successfully completed your tracking and adjustments – the “Copy to Clipboard” function works fine in most cases.

• When importing the data to After Effects CS4, you will have to be sure that your composition size is EXACTLY the same as the original footage file size that you got your track in Mocha from, as well as the file you’re using as your insert footage. Paste the data from the clipboard directly onto your insert footage layer int he Timeline. NOTE: Be sure that you paste this data at frame 0 or it will not match up!

• You will most likely have to nudge your insert footage layer’s Anchor Point to tweak it into the precise position.

THEN – if you are lucky and haven’t overlooked anything, you MAY get a good track. Don’t forget that many others before you have made all the mistakes already, so don’t give up! 😉

Click on the image to view the QuickTime movie of this workflow example

Stay tuned for information about an upcoming training video on all kinds of Motion Tracking, Stabilizing and Compositing techniques!
**EDIT: New training DVD, “Learning After Effects CS4” is now available on the right –>

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