After Effects – More Camera Tracking

In class we continued learning about a few more features in After Effects: Warp Stabiliser and 1-point Camera Tracker. We had two separate exercises to complete, although the second one for 1-point tracking was certainly challenging, if only because the software didn’t seem to want to cooperate and I had to redo the entire endeavour a few times.

For the first time, we were learning to work with DPX files. A DPX stands for Digital Picture Exchange and is “a common file format for digital intermediate and visual effects work” (according to Wikipedia). It won’t be unusual to work with DPX files in the industry, but you do need to change your project settings in After Effects to accommodate for it.

projectsettings

First and foremost, we were taught how to use Warp Stabiliser on less-than-ideal footage, in an attempt to fix it a little bit. This footage was taken by Peter outside of the school just for an example, but it shows a marked difference between the original and the edited versions. Unfortunately, there isn’t much to do about the continued stuttered look, unless a lot of manual editing is done to the frames.

To do this is very easy in After Effects: you just have to choose the footage you want, go to Effect > Distort > Warp Stabilise VFX. Much like when we did the 3D tracking, we needed to turn on the Detailed Analysis and let the footage be processed (which took a couple of minutes). That was pretty much it.

warpstabilizerdetailedanalysis

We were also shown how to fix the fish-eye effect going on in the footage using Optics Compensation. This is also under Effects > Distort > Optic Compensation. The default setting is to actually cause curvature (so further distort with a fish-eye), but we wanted to “straighten out” the footage instead.

opticscompensation

This is done by ticking the Reverse Lens Distortion in the effects window, then fiddling with the Field of View (FOV) numbers. It’s really just down to adjusting the settings until you think the footage looks better. This should likely be done before doing the Warp Stabiliser, though.

After that, we opened up new footage to try out 1-point Camera Tracking, where the goal was to add a fish graphic to the side of a building. I’m not sure if it was because the steps were rather long and slightly complex, but this did take me a few tries to get before the tracking worked correctly. I had issues with the Null object snapping to a different part of the screen, as well as the tracking being rather jagged the first few times I tried to analyse forward.

In any case, I got there in the end with further tuition from Peter and a little more patience. There should be a very exact way to add the objects into the scene, so that there wouldn’t be any mistakes along the way. The steps I followed varied each time, trying to fix what I’d done wrong the last time, only to introduce something else not working right!

Bringing in the footage, the Mr Fish image, and adding a Null Layer was the first step. The first few times I added the Null later on and the project didn’t seem to like that. Parenting up the Mr Fish image with the Null, I moved to setting up the Tracker in the scene.

tracker1

Clicking Track Motion in the menu will add a square to your scene and open up the motion source in a new layer. From there, you can resize the track motion square and place it at a point as close to the object you’re tracking as possible. It also helps to pick a point of high contrast, such as the drainpipes on the white building in the footage.

From there, it’s simply a matter of clicking on the right arrow for “Analyse Forward” and let the computer do the work.

scenetracker

This will add multiple tracking points to the scene, as above (a screencap from the middle of the 200 frame footage). Once you’ve analysed, you can click on the Edit Target button, which brings up a new window.

edittarget

This was why it was important to add the Null to the scene before doing this, as it will now be the layer you’re applying the motion to. The null will contain the fish and a square object behind the fish the same colour as the building.

Making sure that the rectangle shape is also parented up to the Null object, rearrange the objects so they sit on the building properly (we added a blur on the rectangle to blend into the building and a transparency of 70% on the fish image). Finally, you needed to turn on the Motion Blur for all the layers. The end result actually looked quite good:

1pointtracking

We also quickly looked at 2-point tracking, which shares all of the same principles/steps as 1-point tracking, except instead of only assigning on tracking point, you create a diagonal line with 2 points.

tracker2

trackeroptionsAnalysing it will result in the many tracking points above. The same rule applies: the highest contrast, the bigger squares, and the further the points… all of this will result in a better tracking line.

This is done by ticking the boxes for Rotation and Scale in the Tracker menu, instead of just using the Position to track motion (like we did in 1-point tracking).

I think the resulting footage looks really cool and I have some ideas of how to personalise this sort of tracking effect for any future projects!

2pointtracking

 

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