Animation is a technique in which a series of minutely changed still images called 'Cels' such as drawings, objects, posed people seem to come alive, when they are flashed at a fast rate at which the brain interprets as movement. Animation on computers is one of the chief ingredients of multimedia presentations. There are many softwares applications that enables you to create animations that you can display on a computer monitor or on a big screen.
• Principles of Animation : The principles used in animation is the same as used in movies and in TV communications i.e. a biological phenomenon known as 'persistence of vision'. An object or image seen by the human eye retains there for a brief time (1/10th of a second) after the image gets disappeared. When a series of images that are changed very minutely and are moved very rapidly, one after the other, they appear to blend smoothly into movement.
In TV system 25 frames or pictures are shown twice so the rate becomes 50 frames per second. When minutely changed50 frames are moved in one second, the human eye sees a motion picture. To make an object travel across the screen while it changes its shape you have to just change the shape and also move or translate it a few pixels for each frame. Then, when you play it at faster rate, the changes blend together so that you have animation.
• Animation Techniques : When you have to create an animation, first of all you have to collect all the activities you want to add. If the activities are complicated then you can write a script with required objects. Choose the different animation tools required for the job. Build the sequence. Add the lighting effects. Experiment with the images and sequence again and again add some other effects such as sound to make stunning animation presentation.
• Cel Animation : Cel animation starts with a stack of papers. The animator draws his/her characters on the papers, one at a time. One stack of papers would equal to scene of animation for the character. When shooting the animation on film, this paper stack is placed under an animation camera and photographed, one frame at a time. When the resulting film is played back, the sequence of drawings appear to move. This is called pencil-test.
One the animator has the pencil-test footage drawn the way she/he wants it, the animation is traced or photocopied onto the clear sheets of acetate, called "Cels". These cels are painted with an opaque acrylic-based paint to color in the characters. At the same time, the backgrounds are painted, usually in water color. The final animation goes under the animation camera and is photographed frame by frame, with each cel laid over the background one at a time. This footage is final color version, to which sound is added.
• Keyframes and Tweening : Keyframing is the animation approach used in traditional cel animation. The animator starts by specifying the positions and orientations at various key points in time. The "Keyframes" are usually the first and last frame of an action. Then other frames are added in-between to make the effect continuous. The series of frames in between the keyframes are drawn in a process called "Tweening". Tweening action requires calculating the number of frames between keyframes and the path the action takes.
• Computer Animation : In early days, it was very difficult and tedious work to produce animation effects. Because the still pictures were hand drawn in thousands. But these days, this process has been streamlined a bit. Pencil drawings are scanned into a computer, assembled in an animation program and viewed on the computer screen. Changes can be easily rendered.
Once the pencil animation is completed, the drawings are painted in the computer using a paint program. The final color animation can then be exported to videotape or to film.
Disney uses a propriety laser system to transfer their feature animation to film. "Beauty and Beast", "Aladdin", "The Lion King" were all produced this way.
• Kinematics and Morphing : Kinematics is that branch of mechanics that describes the motion of bodies without considering the forces required to produce and maintain the motion. For Example, a walking man. Animating a walking step is tricky. You have to calculate the positions, rotations, velocity and acceleration of all the joints like elbows, knees, shoulders, head etc. There are some 3-D modeling programs available which give readymade models in various poses. Using these models one can change the size, rotate, drag and can make his own model.
• Morphing : Morphing is a type of animation effects in which one image transforms into other. In morphing interpolations specified points on two or more images create a transitional effect giving the illusion that the first images is changing into the last one. Morphing effect is specially used to mix two images smoothly to create a third one. For example, photograph of a young child can be mixed with a photograph of an old man, using morphing effect to produce a third image which is a combination of both. We can see very interesting result of that young child growing old when we animate a series of steps.