Motion Tracking & Object Tracking inside Cinema 4D: How does the 2D tracking process work

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In this video, we'll take a look at the way a 2D tracker sees the world.

In this video, we'll take a look at the way a 2D tracker sees the world. We'll learn what a tracker is, what a feature is, and how the Motion Tracker uses visual information to analyze the motion involved.

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Transcript

In this video, we'll take a look at the way a 2D tracker sees the world. A 2D tracker device, or gizmo, has two components. The green inner square, is the pattern recognition area. And the red outer square, is the search area. These two squares are always center lined, and the search area is always larger than the pattern area. And here's how it works. The pattern recognition area memorizes the pattern underneath it, using pattern recognition algorithms. And then, goes to the next frame, and searches within the search area, to find where the pattern is. Once the new position of that pattern has been located, the motion tracker aligns the pattern recognition area, to the new pattern found, and records the new two dimensional position of the tracker, for that frame. The motion tracker does this for every frame. And stops only when it can't find the pattern anymore, or when it runs out of frames. Once this process is done for at least seven tracks, but the more, the merrier, the motion tracker goes into 3D solve mode, and applies its mathamatical wizardry to the 2D track data. It can then estimate the motion of the camera, and any moving objects in our shot. The 3D solve, or reconstruction, as it's called inside Cinema 4D, is automatic. And although we have three solving algorithms to choose from, I will only be talking about one of them, the full 3D reconstruction. As you can see, in theory, it's a simple process. But in reality, many unexpected things can happen. We will learn how to deal with them, when we start tracking our footage. You should, by now, have a rough idea, of the inner workings of a motion tracker. Let's start looking closer, at some of the different parts. Let's begin with the trackers themselves.
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