Examining The Use Of Motion Capture Film Studies Essay

Motion capture is a technique that records movements for fields like entertainment, sports, and medicine; it is the process of animating a virtual character through the means of capturing live motion of a human. Motion capture is normally used in games to animate characters and other objects by recoding motion from the human character that normally involves tracking sensors that has been placed in major body parts that require maximum motion and detecting their locations in three dimensional spaces. Motion capture captures human body, facial expressions, camera and lighting positions, and other elements. It measures position and direction and recording by computers. Motion capture for computer animation requires the use of human motion to be implanted onto the motion of the compute. There are two classes of motion capture technology, they are the on-line motion capture devices, and off-line motion capture devices. The on-line motion capture device wherein its main technology is based on magnetic sensors thatare mainly used for virtual reality and online television shows with artificial characters. The off-line motion capture device on the other hand wherein its main technology is based on optical motion capture from different camera views, off-line motion capture devices allow capturing of large motions that are important to maintain outstanding visual effects, it also allows the acquiring of delicate motion to properly convey motion. Motion capture is limited to movements that are possible, but it creates natural movements than manual animation and it saves more time.

Before motion capture was even possible, rotoscoping was used and is still being used by some traditional animation studios to copy motion from films to cartoon characters. Many cartoon studios use rotoscoping, but only a few admit that they use it because they consider it cheating and a desecration of the art of animation. (Menache, 2000, p.2).In the Walt Disney film Snow White, Snow White herself and her prince were rotoscopedin 1937. The rotoscoping device was invented on 1915 by Max Fliescher to make production of cartoon films automated. The rotoscoping device projected live action film frame by frame then places on a lighted table to allow the artists to trace the image into paper. The idea of copying human motion for animated characters is of course, not new, they decided to use rotoscoping to create realistic human motion. Motion capture started in bio mechanic research then moved to education, sports, computer animation, and finally video games as technology evolved and is still evolving until now. Rotoscoping today is still being used in visual effects and character animation. It was originally developed in the early days of cell animation; it can be considered a form of time-delayed motion capture. (Kerlow, 2003, p.338). Two dimensional rotoscoping is used for hand drawn cartoons, while the three dimensional rotoscoping gave birth to what we now call motion capture.

Motion is anything that forms a before and after position, without this, motion is not even possible. Motion capture first requires a motion that is recorded for the skeleton fitting post-processing, second the artist will repeat and repeat the motion that should be taken until the director is satisfied, third is the post processing which its first stage is motion tracking which is used to detect the motion through the joints, and the last stage is the anatomic conversion, it produces the character s motion without interrupting the original motion. There are twocategories of human motion: pose estimation and tracking. Pose estimation is formulated as the inference of the articulated human pose from a single image. (Sigal, 2006, p. 3) Tracking is formulated as inference of the human pose over a set of consecutive image frames throughout the image sequence. ( Sigal, 2006, p.3)Motion capture cannot be produced when the human character cannot exhibit that certain motion, and if the motion was not captured. Once the captured session or data did not meet its requirements or standards, it cannot be fixed for motion capture can only produce and capture live motion, instead the user should recapture the motion where the data went wrong. Captured motion must first be developed in many ways before being applied to robots that are human like. Proper alignment of body parts is essential in order to get the proper animation of the model, or else something might go wrong in the future.

Motion capture is a software that captures human motion to make computer games and computer animation more realistic and true to life by requiring the user or the character to place magnetic sensors in any part of the body that detect individual position and orientation relative to the generator.

There are different types of motion capture system: Electrical motion capture, Magnetic motion capture, and optical motion capture. Electrical motion capture uses technology that tracks motion from sensors using magnetic fields, normally one sensor per body part is enough, a magnetic motion capture, on the other hand, is a technique that is based on receivers that detect magnetic fields. In order to capture the human character s motion, magnetic motion capture uses magnetic sensors that measure relationships in space to a nearby transmitter magnetically,a magnetic sensor measures the position and orientation that is in relation to a transmitter, it requires the human character to wear magnetic sensors around his/her body that are capable of measuring their relationship to a centrally located magnetic transmitter (Alonso, N.D, p.55), and lastly, optical motion capture system, it is a motion capture system that is very accurate and is typically based on a single computer. It is usually used for medical applications and is usually places near the joints for humans and animals. An optical motion capture system does not need wirings because they depend on optical markers that are tracked visually. Optical systems plan positions of cameras in order to track down information. All most all of the optical capture systems can track reflective markers. An optical marker is a reflective ball that allowsa camera to track motion in space. In order to create the 3D position of the object, the system combines information of the different shots taken from different views from different cameras. Optical motion capture has been used to recover the fidelity of the motion of strolling adults, playing children and other lifelike activities. (Boulic, N.D. p.1) The motion capture system is also classified as the outside-in, inside-out, and inside-in system. These systems are where the capture sources and sensors are placed. The outside-in system is placed on the body and by collecting data; it uses external sensors, examples of which are camera based tracking devices. The inside-out system on the other hand collects external sources from sensors that are placed on the body. Lastly, the inside-in system, which sensors and sources are placed on the body, examples of which are electromechanical suits.

Applications that have big benefits from motion capture are industries like medicine, sports, entertainment, and the law. Motion capture is also used in other fields like crash test dummies wherein motion capture is required for automobile safety tests. Non-entertainment applications for motion capture on the other hand are sports, medicine, and physical rehabilitation.

Motion capture in medicine is used for gait analysis, which is useful in medicine for it makes it easy to detect certain abnormalities and changes by accurately separating the different mechanism during the cycle ofwalk by generating biomechanical data. Gait analysis is also used to determine treatment for pathological conditions. It is also used in applications like joint mechanics, sports medicine, prosthetic design, and analysis of the spine.

Motion capture in sports is used to improve the performances of the athletes to analyze and study their movements to improve them and reserve them for future use. There are some motion capture studios that specialize in capturing motion for anything sport related especially for golf, which is very essential to golfers because every inch of his/her swing is analyzed to find and improve on areas, also is compares his/her swing to that of a professional. Motion capture in sports is better than actually videotaping the movement because the normal speed of a video tape is at 30 frames per second, while motion capture is capable of recording higher frequencies, meaning much more motion is recorded.

Motion capture in the entertainment industry is the segment with the highest (of not the largest) profile especially for video games which is the most widespread and the most accepted in the entertainment application. Motion capture for video games is a very used system that requires live human motion. As game engines become faster, motion capture is also maturing. (Menache, 2000, p.34). Motion capture for films mainly involves stunts that are not humanly possible, by using realistic motion and extras like large crowds which are digitally generated to simulate a large number of crowds. Motion capture in law, on the other hand, is mainly used for evidence. The evidence used provides aid and support to help the jury understand the statement of facts and opinion form the witness, by means of action and facial expressions in order to get the case solved. Out of 50 people, 8 disagreed to the statement that motion capture is useful in fields like medicine and the entertainment industry, 6 people agreed, and 21 people were uncertain. This is probably because people do not know much about motion capture that they don t notice it in certain field.

Before deciding to use motion capture, the user should think if the decided motion is possible for a human or an animal to handle. Also, the user should state the expectations and the demands as early as possible so that all of the user s concerns are addressed. The user should also think about the amount and size of markers to be used depending on a given situation so that the markers won t fall off or move around during the session knowing that a performer needs to wear markers that are near joints to easily identify motion. In order to capture simultaneous motion information, the user should equip the human character with the typical tight fitting black motion capture suit so that the markers will not move rather than just attaching invisible adhesive tape to get the natural look of the clothes as it moves. In order to create a virtual character, one must first identify the performer s motion. Always remember that motion capture takes time to produce and that you cannot fix a mistake, instead you must redo it.

If you decide to do facial and body motion for a character, you will need two separate setups, but you may also have one setup for each character, always remember that motion capture requires a frame of reference.

Before getting a human actor to perform all the motion for the motion capture, a script and a blue print must be done first. After which, provide the human actor with the script and the blue prints in advance and tell everything about the character to the human character to avoid misunderstandings in the future. Rehears the motions first without the motion capture sensors so that the human actor will get familiarized and comfortable with his/her role; once the actor is already comfortable and is familiar with the role, get the human actor comfortable with the motion capture sensors that will be all around his/her body soon, always remember that preparations are still needed whether you have an in-house system or are hiring service provider. (Menache, 2000, p.88) in order to create motion capture, one needs to have experience. Out of 30 people, a majority agreed to the statement, while a minority either disagreed or were uncertain about the statement.This is probably because when creating something, one must have an experience, or else nothing productive will happen.

Motion capture must be and must always be precise about the sizes of the character. If the computer model has different proportions from the subject, weird things may occur, an example is that a feet entering the floor because the characters legs are longer than that of the human actors legs. Motion capture requires motion that follows the laws of physics, otherwise it cannot be presented.12 out of 30 people are uncertain about this statement, this may imply that they are not sure whether it is possible to make motion out of anything that do not follow the rules of physics, 16 out of 30 people on the other hand agreed that movements that do not follow the laws of physic cannot be presented maybe because they believe that there will be a lot of errors if this happen, and 5 out of 30 people disagreed thinking that motion capture can generate any kind of motion impossible or not. Motion capture requires live motion, meaning it can only work in real time, although 9 out of 30 people were uncertain whether this statement is true or not, this is probably because some people do not know how motion capture works, but a whopping 23 out of 30 people agreed that motion capture only works in real time.Motion capture system is very expensive and 23 out of 30 people agreed so, it requires hard work and is time consuming for the actors and the technicians, although 21 out of 30 people were uncertain on whether motion capture is easy.Dogs, horses or any animal with four feet can be difficult to capture. 18 out of 30 people agreed that applying motion capture to 4 legged animals could be hard because animals don t actually perform all the time the way we want them to because animals, even tamed one are still considered wild and unpredictable, although 12 out of 30 people were uncertain and 3 out of 30 people disagreed thinking that animals obey every command as long as you treat them well and give them a doggie treat every time they do things correctly. Motion capture techniques are well known for preserving the distinctive signature of the real movement (Amaya, 1996, p.1) coming from the human actor. In spite of this, motion capture involves the use of special equipments; this requires the entire motion session to be recapped once a motion session is different from the already captured one. What I basically did was I looked for scholarly articles on the internet, gave out surveys, looked for books in the library that were related to my topic, and placed interesting or related texts on my note cards and paraphrasing them so that writing the actual research paper would be easy considering that you will just copy what is on the back of the note cards. A majority of the people who took part in my research paper were students from Computer Science in De La Salle University, and a minority came from Psychology Students from the same University. The results were reasonable and I would have said the same randomly if I did not research about the topic. The results mean that motion capture is applied in our everyday lives whether we know it or not. Compared to the 2nd research, the 1st research was all about the opinion of other people on how they know about motion capture. Though impressive in its ability to replicate movement, the motion capture process is far from perfect. (Boulic, 1998, p.1)