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Cool Matrix Filming Techniques

Posted by emmett on from the kung-fu-camera dept.

webword writes "Here's how those cool scenes from the Matrix were filmed (go here). Not that I want actually buy one of these cool cameras, but I hunted around to find out how to get one and how much they cost. You can get one here. This brings up a quick question: How are people keeping up with the latest and greatest filming techniques?" What? An advance in cinematography that doesn't involve a farm of Linux machines?

1 of 155 comments (clear)

  1. Cameras are only a tiny part of the story by cying · · Score: 5

    I know one of the people who did the R&D on bullet-time sequences in "The Matrix"; he recently gave a seminar at U.C. Berkeley along with Jon Gaeta where they discussed how the bullet-time sequences were done.

    First, the difference between bullet-time sequences and the GAP commercial sequences is a big one:

    Freeze-time shots (e.g., the GAP commercial) are easy to do. All shots are taken simultaneously of the scene, and you don't need to worry about the motion of the subjects in the scene.

    Bullet-time shots actually have to move in very slow motion. At the seminar, they said that although they had many cameras firing sequentially over the camera path, they were unable to place cameras close enough together to capture sufficient frames during really slow segments of movement (if you watch The Matrix bullet-time sequences, you'll see that initially the motion starts out very slow, and gradually speeds up)

    The way that Manex solved this was to use computer vision techniques to interpolate the necessary "in between" frames. This is especially difficult since the motion in some shots (i.e. Keanu Reeves' arm waving in a circle in the air) have motion that isn't linear (meaning that the compute can't simply compute the pixels along a straight line from one frame to another). Manex used a lot of combined interpolation techniques to achieve the results in the movie.

    In addition, obtaining consistent camera lighting, film grain, and film speed parameters proved difficult. They used cameras that were all uniform in make and model, but had to image process the frames to achieve consistency.

    Second, you may notice that all bullet-time sequences were captured on a green screen! One of the reasons they did this was because the angle of rotation is actually more than 180 degrees. (This is also a difference from the GAP commercial) So how did they insert the background?

    Well the answer is, they re-created the backgrounds. Manex used image-based modelling and rendering techniques that were based on work done by Dr. Paul Debevec at U.C. Berkeley. You can read more about the FACADE photogrammetric modelling system and The Campanile Movie (which I helped work on) by following the link.

    Manex's techniques greatly improved upon the work at U.C. Berkeley; they showed an OpenGL real-time demo of the sub-way and government building lobby shots from the movie at the seminar; very cool stuff.

    Hope that sheds some light on how effects in The Matrix are really done.

    -- Charles