Adding graphical elements or entire environments to a video is sometimes the best solution to visually explain a concept or inner workings of a system. For example, holographic projections of a room with a base-plate of an actor walking around and interacting with parts of the room requires filming the actor, and then tracking the camera movements of the filmed footage to match its motion in the real world, to that of the 3D software “world”. This time consuming task can be made easier and faster thus less expensive by filming the actor with high-contrast motion trackers in the environment thereby avoiding some unsolvable camera movements throughout the footage. Our video production team not only produces beautifully focused and lit video imagery, but can also film while keeping 3D camera tracking in mind to keep overall production time and costs lower than it would be without the preparation and foreknowledge needed for this task.
The other kind of tracking where you don’t need the environment altered but rather some moving object in the footage in order to, for example, replace it with a lightsaber. This task requires the actor to wield or interact with an object that is properly marked with contrast-points for easier tracking in post production. Then, after the lightsaber or rocket launcher is modeled and textured in 3D software, the tracking information is used to make it translate, rotate and bank exactly like the tracked object in actors hands. An important part of object tracking is to make the tracking object, which the actor is holding in video footage, similar in length and to have logical holding points that make sense on the object that it’s going to be replaced with. Also, the actor has to act out the weight of the final object or it should have similar weight on its own.
Object tracking also includes more real world needs like tracking a mobile screen to replace its screen with animated user interface or holographic projections being projected by a wearable device. It’s not all lightsabers and rocket launchers.
To make tracked environments or objects really fit in with the filmed footage, the 3D part has to then be lit similarly to the lighting in the original video but masked to hide whatever is behind the actor and what’s in front. Then the footage is color corrected and graded to look good and make it look even more like it was filmed at the same time. But that’s a whole new topic to write about another day.