3D Tracking to a Moving Object

[Walter Soyka]

After Effects CS6 has a new, built-in 3D camera tracker [link] that should be of immense help on this shot.

For previous versions of AE, a third-party 3D tracker like The Foundry’s CAMERATRACKER (AE plugin) or SynthEyes (third-party software) will be necessary.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Chris Tarroza]

Thanks Walter. I know the new camera tracker will track the camera movement, but will it also track to the cyclist? If I were tracking to a stationary object, this would be easy enough, but since the cyclist is also moving, not too sure on that…yet.

[Walter Soyka]

Could be very tough with the built-in tracker since it doesn’t offer a lot of control. You might be better off with SynthEyes (see this tutorial [link]).

That said, with a little elbow grease, you may be able to get a pretty nice result by using the built-in tracker to solve for the camera, then parenting a 3D null to the camera and manually tracking it to the bicycle.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Roland R. kahlenberg]

mochaAE/mochaPro will be better suited for this job. After all, you’re committing to a basic transform track.

HTH
RoRK

Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer

[Walter Soyka]

[Roland R. Kahlenberg] “mochaAE/mochaPro will be better suited for this job. After all, you’re committing to a basic transform track.”

I was thinking that the cyclist would be tough for a planar tracker — but Roland really knows tracking, so his opinion carries a lot more weight than mine.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Roland R. kahlenberg]

The helmet and the bike’s body are good shapes for a planar track.

With Version3 of mochaAE and mochaPro, you can also camera solve a scene and include points for moving objects as shown in this video –
mocha v3 tutorial: Camera Solving for Moving Objects

I would go with the 2D track as a first alternative.

HTH
RoRK

Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer

[Chris Tarroza]

Thanks Roland and Walter.

I’ve never used mocha but if it’s the way to go for this effect, I’ll take the time to learn it. I watched through the tutorial you posted and just have a few questions. Although the surfboard tracking had some 3D motion in it, the movement was more or less along the X and Y. The majority of the movement that I need to track will be in Z space.

Here’s one of the shots in question actually. Again the idea is that the text will be tracked above or to the side of the cyclists head and move in 3D as the driver passes by.

https://reels.creativecow.net/film/cyclist

So will mocha do a good job at tracking the cyclist?

[Roland R. kahlenberg]

[Chris Tarroza] ” the text will be tracked above or to the side of the cyclists head and move in 3D”

What do you actually mean by move in 3D?

Anyways, I did a quick track with AE CS6’s 3D Motion Tracker and it did the trick really fast. I also did a track with mocha but not V3, the one with the camera solve feature, and it too did a good track but I had too apply the ‘smooth’ Expression method, with the following settings – smooth(.2,5) to the position and scale properties. The rotation and anchor point KFs from mocha were removed and reset to 0.

FWIW, AE’s camera solve is a faster solution for shots like these. It took no more than 2 minutes.

HTH
RoRK

Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer

[Chris Tarroza]

By “move in 3D” I meant that it follows the camera movement and sticks to the cyclist.

I did do a quick run through with AE’s Camera Tracker. It’s not perfect but it’s pretty close. It does a real good job of tracking the camera movement, but does not track the movement of the cyclist (which I’m sure it wasn’t designed to do anyways).

The camera tracker alone gets me pretty close. Unless there’s another way, I’m just going to have to keyframe the text to get it just right.

Thanks for the help. Much appreciated!

[Roland R. kahlenberg]

[Chris Tarroza] “By “move in 3D” I meant that it follows the camera movement and sticks to the cyclist.”

This can also be achieved with a 2D track that contains position, scale and rotation (z axis).

But like I said, AE’s 3D Cam Tracker should do the trick. The movement of the cyclist is sufficiently slow to ‘fool’ the tracking algorithm to think that it’s a stationary object or part.

If the cyclist moved faster, the algorithm will accept the cyclist as an animating object within the scene and not treat it as part of the solve. That’s how I’ve understood how AE’s camera solves work.

Anyways, back to your video, here’s something I put together rather quickly – https://www.broadcastgems.com/mediastreamer/16538_R01.mp4

After the camera solve, I selected a solved point on the helmet and created a camera and text layer. I then moved the text layer in z-space, away from the camera so that it was in front of the cyclist (its helmet). Then a wee bit of masking (rotobrush is another option) did the trick.

It’s really a quick process once you’ve wrapped your head around the process.

HTH
RoRK

Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer