After Effects – Even More Tracking (Planar)

I won’t go into massive detail about the first part of the lesson, since a lot of it was re-visiting 1-point tracking; the main topic of the class was learning planar tracking with Mocha. The one neat thing we learned just as we were starting out was: bringing in the footage we want to use into the project, we can create a composition that matches the footage settings by click-dragging the footage to the “Create a New Composition”. This makes it so much easier to match your composition to your footage and I’m glad to have learned this now!

A lot of my instructions for this tutorial could be found in the blog post I did here – it was a lot easier this time around, since the instructions felt more intuitive after our previous weeks doing tracking. The main goal was to attach some smoke to a chimney that could be see throughout half of the footage. I think it turned out quite well!

trackers1

The biggest difference this time was that the smoke would only be seen for a brief period of time on screen (about half of the footage). After doing the Analyse Forward the first time around, we’re given the usual tracked line across the screen. After that, you can see that the tracked portion (the chimney) goes off screen, so we need to offset it. By Alt-Clicking on the white tracker box to reposition it to another point further along the scene (we picked the shaded area near the house window), we could then press the Analyse Forward again to add onto the line.

tracker-reposition

As can be seen above, the original tracker point goes off screen due to moving the box. This means the smoke will go off-screen after being parented to the tracker Null.

Following this, we moved on to Mocha – something I was very much looking forward to since hearing about it before Christmas! We first needed to import the footage we would be using (a tunnel, with some camera shaking to get the full understanding of what Mocha can do).

Importing the footage to track in Mocha is as easy as (1) highlight the footage layer, (2) go to the animation menu, and (3) select the Track in Mocha AE option. This opens up Mocha, which is a lighter version of the full software now built into After Effects.

Looking through the footage, we needed to find a spot where we’ll be able to set up the region we want our image to be. This was done by using the X-Pen tool and drawing out the shape on the wall, then right-clicking to finalise the shape.

mocha-planar-shape

After that, we needed to click on the Show Planar Surface button and a new, blue box showed up – this would be used to determine the size of the image you want to impose on the tracked footage. I made mine a bit smaller than the red image, which seemed to work out. In order to actually set the tracking, we needed to track backward through the footage to its start, then track forward (from about one frame ahead of where you tracked backward from, so you don’t miss any frames).

To finish off and bring the tracking back into After Effects, we clicked on the “Export Tracking Data..” and copy that to the clipboard.

Making sure we were back on the first frame in After Effects, we just needed to add a Black Solid to the layers and paste the tracking data while the layer is highlighted.

paste-track-data

Scrubbing through, I could see that my shape was there and ready to be used with the tracking data intact! I had to PreComp the Black Solid layer, then open it up to add the image as the top layer in the composition; we also had to resize the image to Fit To Comp so it would fill out, although I suppose there was also to option of resizing the image ourselves should we want to have less skewing.

Finally, it was merely a matter of changing the blending mode, opacity, and enabling the motion blur for the layer and the composition – I think it looks very shiny!

trackers2

As a second example, Pete provided some footage of a train going by and asked us to apply the same steps in order to add some vector text .png to the side of the first carriage. This was made very easy with Mocha’s tracking abilities – I really think the program is amazingly good at what it does!

trackers3

I really like this sort of tracking, since Mocha makes it interesting and a little easier than the point tracking in After Effects. I believe there were other bits of footage in the folder, so it’s possible we might have practice this more in class, but hopefully we’ll do more on this in class next week. Otherwise, I’d like to give it a try myself with some experimenting and different kinds of scenarios! Overall, I really enjoyed this lesson and found it very straight-forward. I do remember I had more issues getting the Nulls to work with the point tracking, but this was a very smooth process.

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Posted in VFX

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