Tutorial: After Effects CS6 3D Camera Tracker
In the above video, Jon Carr, demonstrates the new 3D camera tracker in Adobe After Effects CS6. The tutorial covers two different uses of the camera tracker: incorporating 3D text and also basic visual effects.
The 3D camera tracker is incredibly easy to use. Once you have your clip imported and you have created a new composition with it, you simply right click the clip and select "track camera". After Effects will analyze the shot for you and apply a multitude of tracking points throughout the shot. The difference in color between the points doesn’t mean anything – it’s just a tool for differentiating between them since there are so many. However, the size of the points denotes which of those points are closer to the camera (in the virtual space that the 3D camera tracker has built using 2D track points and 3D solve points).
After you have your points mapped out, you may want to refine them a bit. Under the advanced tab, you can check out the average error to see how accurately your scene has been mapped. The value here is the average distance between the 3D solve points and the 2D track points. In our example we came out with an error of 0.71 – which is pretty good. Generally though anything that goes above 1.0 may cause you some issues, and so you may want to further refine your camera track. There are a couple different ways you might go about this. First you can remove points that are not attaching to the scene well (perhaps something passes through your frame and throws them off) by using the lasso tool and simply deleting them so AE is not using them to solve the camera. Additionally, if you are still having trouble – you can give the camera tracker a little more information to work with by letting it know any of the following: you are using a variable zoom in the shot, you are panning or tilting on a tripod, or that your camera is completely still (so it doesn’t track the camera to character action).
In order to apply 3D text to your shot, you must select a point (or a number of points) that you want the text to "follow" (your 3D image will be bound to the camera that is created by the tracking of these points). This is easy to do – simply right click and select "create text and camera." The text will appear on your screen next to the tracking point which you selected. You can now edit the text, adjust its size, font, origin point, etc. In our example we also adjusted its orientation so that it appeared to be standing upright, as opposed to laying flat – which was its default. You can also apply other effects to your text as well. In the tutorial we add a shadow and light to the text using the same selected points to create a flat plane (which you can’t see) that catches the shadow of the text, which we were able to refine into the shape of the top of the building. Of course there are many other effects that you can add to your text to create some visual interest – you should experiment. You can also change what renderer AE using (top right corner of viewer window). The default is the Classic 3D renderer, but you can switch of to Ray-traced 3D – which will allow you to extrude your text into a 3D shape. A word of caution though – this requires a fast machine. It’s possible to drop the resolution of the rendered effect (we had to drop to "fast draft") in order to lessen the taxation on your system, but it still requires some heavy processing power.
You can also use the camera tracker to create visual effects. In our tutorial we do a simple visual effect, replacing the number on the helipad of the US Bank building. However, you can use these same principals for dropping in 3D elements, rotoscoping, sign and background replacement, etc. To do this, first make sure the layer with your visual effect on it is a 3D layer (so that it exists in the same virtual space created by your 3D camera tracking points). Next, select the point or points you want to bind your effect to, right-click them, and create a null object. You then need to select the pick whip on your visual effect layer and drag it to the null that you just created. This parents your visual effect to the null and orients it for you in the 3D space so that you don’t have to fumble around with key framing the effect on the X, Y, and Z axis.
Please make sure to watch the video for a more in depth explanation of the 3D camera tracker and some of its uses. The 3D camera tracker is an incredible new tool that comes with CS 6, and it makes dropping effects into your scene easier than ever before.