Motion Tracking & Object Tracking inside Cinema 4D: Tracking the Survey shot Basic Camera Tracking

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In this video, I will show you how to do the simplest form of camera tracking, using a mere few clicks.

In this video, I will show you how to do the simplest form of camera tracking, using a mere few clicks.
We are going to track the Survey Shot. Please refer to the video named "The Project Footage" to see where to download the relevant footage.

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Transcript

In this video, I will show you how to do the simplest form of camera tracking using a mere few clicks, we are going to track the survey shot. So let's begin. Let's go to the motion tracker menu and add a motion tracker object. With a motion tracker object selected, let's go to the footage tab and click here to load the footage. Let's find the blaster survey sequence and just double click on any of the frames. And you will see that the footage is loaded, but it's a bit squished because of the pixel aspect ratio. Let's correct that, let's go to film aspect and select 16 by 9 and that is because I know it's 16 by 9. Number two let's change the resampling to 100%, so the image is fully sharp. Now let's fix our rendering output although it doesn't make a difference in this scene, we'll do it anyway. So, I'm going to make this 720, press enter and now we have a full frame. As you remember from the previous videos If you saw them, we will go to 2D tracking, start pressing these buttons and whatnot. But that's not what I'm going to do. I will go to the motion tracker menu and select the full solve. What the full solve does is it adds the automatic tracks, It does all the process of replacing the lost tracks, it follows these numbers here and it tracks bi-directionally. And after it's done with the 2D track, It's actually going to give us a 3D camera solve. And I think it's already done if you look down bottom left you'll see it says running 3D solver, and we will see that prompt. And I think in just a few seconds, I'm letting this run in real time so you get an idea of what kind of times you should expect with these settings. Changing these numbers will impact the time it takes for the solve. I think in a few seconds it's going to be done running 3D solver. Maybe five seconds pre-optimizing, optimization, and deferred solve finished. When you see this, that means that your 3D solve is done. Now what we see here in our screen these purple little dots, these are the 2D trackers. And if I scrub through, you'll see those little squiggly lines. Those show us where the tracker came from 10 frames backward, and where the tracker is going 10 frames forwards. By watching these little shapes, you can estimate if a tracker is going off on its own tangent or not. If you see that there's uniform shape between these paths, these tracks then you are safe to assume that the tracker is actually following the proper camera position. Whereas if one tracker a has a very different shape to the ones around it, that means something is fishy. Other than this cryptic message, there's nothing else to indicate that the solve has happened. So, what I'm going to do is click on this, and you will see that we have the solved camera. And you can see when I click on it, the horizon. And we have this null that contains the auto features. If I untwirl this, you'll see that the features which are basically the nulls that are in the 3D positions represented by the 2D tracks are sorted with the highest quality on top and the lowest quality on the bottom. And you can see that reflecting in their color. We'll see how to use them later on. Now you can obviously see if we go to the four views, and what I'm going to do is click here, press H to fit everything. Click here H, and click here H. This is a very clear view of what's going on. We are actually seeing the floor of the survey shot at a different angle. And that's a very natural thing that happens. The tracker does not know if this is a floor, or if this is a wall, or if this is a ramp because everything is virtual. We can tell from this view that this is the floor. And although at this particular moment we don't need to do anything else with the survey shot other than go to the solve camera and copy the focal length which we are going to use to track the other shot, and this is one of the purposes of the survey shot. I'm going to show you a little nifty trick. So I'm going to maximize this view, and I'm going to select the motion tracker, and what I'm going to do is zoom out, and use my rotation tool to rotate the whole system. So that this is pretty much aligned to our floor. The next thing I'm going to do is get my move tool and move this so that this is close to our world zero. You can see that there's a vertical distribution and if we correct the other rotation this one. I can press R to rotate, and rotate it this way and then move it slightly down. What I'd like you to pay attention to is this curve that happens. This curve indicates that the lens has some sort of distortion, but as I told you before it happens at the edges mostly whereas at the center of our image, It seems to be quite okay. And that is why all the features around our frame seem to have a higher error threshold because of this distortion the tracker found them erroneous so to speak. Anyway, I'm going to wrap this up by doing an interesting thing. I'm going to take a cube, and I'm going to make sure the cube is sitting on the floor. I'm going to make the cube a bit smaller, bring it down, so it's touching the floor, and align it over here and rotated around. Because I know that these points indicate that there is a floor here, if I go to this view rewind and press play you will see that the camera is moving. If I select the camera, you can see the camera is moving. This is the path of the camera when the cameraman shot it. It has been calculated by the motion tracker. And here you see the full 3D reconstruction of our scene. And you know something, for a couple of clicks it's not at all bad.
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