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VISUAL TECHNIQUES IN ANIMATION

CONTENTS
1. INTRODUCTION
1.1 Animation
1.2 Conventional and Computer-assisted Animation
2. VISUAL TECHNIQUES IN ANIMATION
2.1 Inverse Kinematics (IK)
2.2 Motion Capture (MoCap)
2.2.1 Facial Animation
2.3 Motion Blur
2.4 Combustion / Explosion
2.5 Environment Effects
2.5.1 Fog Effect
2.5.2 Underwater Effect
2.6 Morphing
2.7 Particle Systems
2.8 Lights
2.9 Texture / Mapping
3. APPLICATIONS OF ANIMATION IN REAL WORLD
3.1 Advertising
3.2 Film-Special Effects
3.3 3D- Cartoons
3.4 Scientific Visualization
3.5 Architecture
3.6 Flight Simulation
3.7 Game Developement

4. CLOSING WORDS


Introduction

Animation:

To ‘animate’ is literally, to bring into life . Although people often think of animation as synonymous with, it covers all changes that have a visual effect. It thus includes the time varying position, shape, colour, transparency, structure, and texture of an object, and changes in lighting, camera position, orientation, and focus, even changes of rendering techniques.
Animation is a graphic representation of drawings to show movement within those drawings. A series of drawings are linked together and usually photographed by a camera. The drawings have been slightly changed between individualized frames so when they are played back in rapid succession (24 frames per second) there appears to be seamless movement within the drawings.
Animation is widely used in the entertainment industry, and also being applied in education, in industrial application such as control systems and heads-up displays and flight simulators for aircraft, and in scientific research. The scientific applications of the computer graphics, and especially of animation, have come to be group under the heading scientific visualization. Visualization is more than the mere application of graphics to science and engineering, however, it can involve other disciplines , such as signal processing , computational geometry, and database theory. Often the animations in real visualization are generated from simulation of scientific phenomena. The result of the simulations may be large database presenting 2D and 3D data; these data are converted into images than then constitute the animation. At the other extreme, the simulation may generate positions and locations of physical objects, which must then be rendered in some form to generate the animation. This happens for example in chemical simulation , where the positions and orientation happens of various atoms in a reaction may show a ball and stick view of each atom or may show overlapping smoothly shaded spheres representing each atom. In some cases , the simulation program will contain embedded animation language , so that the simulation and animation processes are simultaneous.


Conventional and Computer-assisted animation:
A conventional animation is created in a fairly fixed sequence: The story for the animation is written (or perhaps merely convinced), then a storyboard is laid out.Astoryboard is ananimation in outline form – a high level sequence of sketches showing the structure and ideas of the animation. Next , the soundtrack (in any) is recorded, a detailed layout is produced (with a drawing for every scene in the animation), and the sound track is read – that is , the instant at which significant sounds occur are recorded in order. The detailed layout and sound track are then correlated . Next certain key frames of the animation are drawn – these are the frames in which their entities being animated are at extreme positions, from which their intermediate positions are can be inferred. The intermediate frames are then filled with (inbetweening ), and a trial film is made (a pencil test). The pencile test frames are then transferred to cels (sheets of acetate film), either by hand copying in ink or by photocopying .Then these cells are coloured , and assembled into correct sequence; then they are filmed .
Because of Key frames and inbetweening , this type of animation is called key –frame animation .In computer base systems the same operation is carried out , but in now a days ,animator only gives initial and last positions of the objects ,and inbetween frames are drawn automatically by the software.
Many stages of conventional animation seems ideally suited to computer assistance, especially inbetweening and coloring, which can be done using a seed-fill technique. Before the computer can be used , however the drawings must be digitized . Digitizing can be done by using optical scanning , by tracing the drawings with data tables, or by producing the original drawings with a drawing program in first place. These drawings may need to be postprocessed to clean up any glitches arising from the input process and to smooth the contours somewhat .







VISUAL TECHNIQUES IN ANIMATION:

INTRODUCTION:
There are many visual techniques in computer animation. Some of them are as follows :
§ Inverse Kinematics (IK)
§ Motion Capture (Mocap)
§ Motion Blur
§ Combustion / Explosion
§ Fog / Underwater Effect
§ Morphing
§ Particle Systems
§ Lights
§ Texture / Mapping

These techniques are used to simulate the complex or realistic motion of object and characters. Many of these techniques in fact start by “capturing” the motion of real actors and applying it to animated characters .This presents the hybrid environment in which some of the latest animation techniques are almost used in combination with others .The main reason for using hybrid environment is the fact that natural motion is too complex to be reacted with just one techniques.

Inverse Kinematics:
Inverse Kinematics (IK) techniques are useful for animating complex models with large no of joints. Unlike other counterparts: forward kinematics, Inverse Kinematics technique determine the motion of entire skeletons based on the final angle of some of the key joints that defines the motion . Forward Kinematics calculate the motion and final position of model by first specifying the angles of it’s joints . That is, in essence ,the Inverse approach to Inverse Kinematics .
Inverse Kinematics animation techniques require that 3D models tube animated are built as hierarchical structures. Inverse Kinematics (IK)are most commonly applied to articulated figures that are defined as hierarchical skeletons constructed with links that are connected by joints , each with different motion constraints .




IK skeleton

Inverse Kinematics (IK) technique can greatly simplify the animation of models with multiple joints that move in a complex but realistic way .E.g. In trying to animate running tiger with interactive specification of key frames could turn into a long, tedious process of trial and errors, especially if tiger is running on an uneven terrain that had obstacles scattered along the way, but the same process could be simplified using IK because this animation tech. uses the position of joints in an articulated figure to animate entire figure into the desired configuration. If only inverse kinematics technique is used then there‘ll total disorder in the motion of character. In Forward Kinematics, motion is inherited DOWN the hierarchy from the parents to the children. In Inverse Kinematics, motion is inherited UP the hierarchy, from the extremities to the more proximal joints (closer to the body) which are their parents.

This effectively allows an entire arm or leg to be posed by moving one object: a GOAL (or ``handle'' in other programs). As the Goal is moved around, the extremities follow it, and the joints above it in the hierarchy readjust accordingly. In order for the joints to readjust appropriately, constraints or ``degrees of freedom'' have to be assigned to the joints, so they don't bend beyond a realistic range of motion.








Motion capture:
Motion capture is an attractive method for creating the movement for computer animation. It can provide motion that is realistic, and that contains the nuance and specific details of particular performers. It permits an actor and director to work together to create a specific desired performance, that may be difficult to describe with enough specificity to have an animator re-create manually.
Motion capture can be an effective method of creating realistic human
motion for animation. Unfortunately, the quality demands for animation place challenging demands on a capture system. To date, capture solutions that meet these demands have required specialized hardware that is invasive and expensive. Computer vision could make animation data much easier to obtain.


Human model for Motion Capture
In Motion Capture technique, there will a model (usually human) on which sensors are glued or fixed. The sensors are fixed on joints, for better capturing the movements. The sensors are may be in the form of
1. Optical sensors (for example: light bulb as shown in image above)
2. Electric sensors
In capturing the motion more than one cameras are used . Each one will capture from angle so that final we can get 3 dimensional motion of moving object. The images obtained from various cameras are processed and according to the motion of sensor points, the motion to according wireframe is given . Wireframe model is nothing but the simulation of actual model on which sensors are fixed.

Wireframe Wireframe with Skin
One cannot represent the Wireframe model to user but that Wireframe model has to be skinned. The reason for this is, the presentation looks more real . There are various algorithms for skinning a Wireframe. The obtained motion from cameras are attached to the Wireframe, it may be an actor from a animated movie , or a non-living thing like pencil. Using Mocap one can make live a non-living thing , by attaching actual model’s join points with non-living object’s joints.
The use of Mocap Technique is used in following fields ,
1. Animated movies (as explained above)
2. Tele-surgery

In Tele-surgery, doctor will not be present in the hospital at the time of operation but he can be on other side of the globe. There will be a camera on doctors place and sophisticated robot system at hospital end . Doctor will get information through the live–camera placed in hospital . According to the conditions , the doctor will just move his hands in front of his camera . His actions will be captured and processed though software , and specific instructions will be given to the robotic arms in hospital. And operation will be carried out successfully .


A complete motion captured sequence simulated on virtual actor


Facial Animation:
Facial Animation is one of the main applications of Motion Capture Techniques .Facial animation is now attracting more attention than ever before in its 25 years as an identifiable area of computer graphics. Imaginative applications of animated graphical faces are found in sophisticated human-computer interfaces, interactive games, multimedia titles, VR telepresence experiences, and, as always, in a broad variety of production animations. Graphics technologies underlying facial animation now run the gamut from key framing to image morphing, video tracking, geometric and physical modeling, and behavioral animation. Supporting technologies include speech synthesis and artificial intelligence. Whether the goal is to synthesize realistic faces or fantastic ones, representing the dynamic facial likeness of humans and other creatures is giving impetus to a diverse and rapidly growing body of cross-disciplinary research. The panel will present a historical perspective, assess the state of the art, and speculate on the exciting future of facial animation.

The Pixar studio produces broad-based acting in feature animation; hence, the most important considerations are facial appearance and the meaning that the face conveys. Hopefully, before an animator begins working on the face, the character's body has been well animated and/or possesses the proper attitude. A good strategy is to draw ``thumbnails,'' small sketches of the desired appearance of the face. Here an animator should think about the graphic design both in the small and in the large; from the relationship of one eyebrow to the other, to the interrelationship of all the facial features, to how the face relates to head position relative to the camera and perhaps even in the context of adjacent shots. The goal is to compose a graphic design with all its elements in place. None of the components are arbitrary and they all contribute towards the final effect.



Motion Blur:

Motion blur is an effect you will see in photographs of scenes where objects are moving. It is mostly noticeable when the exposure is long, or if objects in the scene are moving rapidly.


A camera works by exposing a sheet of light sensitive film to a scene, for a short period of time. The light from the scene, hitting the film, causes the film to change chemically, and eventually results in a picture representation of the scene. This is known as an exposure. If the scene changes during that exposure, a blurred image will result.
You will see motion blur to some extent in almost every film and TV program. It is likely, however, that you will not notice it. Like many artifacts of photography, you only usually notice it's absence, and it's presence gives an air of realism.
For example, you may have seen that lens flare has become a popular effect recently. Traditional photographers often try to reduce it's effect, but since we recognize it as an artifact of reality, computer graphicians make the effort to simulate it. The same goes for the grain on film, the wobble of a camera being held in the hand or mounted on a helicopter, focus effects, and many others.
Take a look at some computer animations that do not contain rendered motion blur, and you will see that fast movement looks jerky and unrealistic. You might also notice this effect in TV coverage of sporting events. Whereas most TV programs are filmed with cameras that take about 25 frames per second, sporting cameras can take up to 1000 frames per second, giving excellent sharp slow motion replays. However they broadcast only a small fraction of these frames, which reduces the amount of motion blur, and so fast moving objects seem to flicker.
We are all so used to seeing motion blur in TV programs and films, that to see motion without it looks a little unrealistic. The lack of motion blur is one of the (many) reasons that computer generated animation can look unreal. This lack of realism is caused by the sharpness of motion in computer animations is quite noticeable, and can really spoil the effect.

Creating the effect of Motion Blur in an Image:

The method for creating smooth images is known as Spatial Anti-aliasing (means smoothing out space), and the method for creating smooth motion in animations is known as Temporal Anti-aliasing (means smoothing out time).
It is analogous to the method used to anti-alias images.
1: Render too many frames:
Just as you rendered the images much larger to start with, so you should also render the animations much longer. For example, to create a 4 second animation with 100 motion-blurred frames, you might begin by rendering 400 frames. These 400 frames would cover the same 4 seconds, but would occur 4 times more frequently in time.
2: Divide the frames:
Next, take groups of 4 frames . . .
3: Average:
. . . and mix them together evenly.
4: Done:
You now have a 25 frames per second animation. The motion-blurred frames on the right are 1/25th of a second apart.



These two frames show identical scenes, but one is taken from an animation where the camera is traveling forwards quickly, in the other, the camera is moving to the left. Is should be obvious which is which. During an animation, your brain will notice this extra information, the motion will appear smoother, and the final effect will be a more realistic animation.

Combustion / Explosion:
This is one of the most fascinating special effects used in Hollywood movies . The most amazing part about creating a material that can be used to create the illusion of fire is that it can be controlled. If you would like to have a bowl of fire and for the fire to drip down off the edges, this is possible. If you would like the fire to travel through pipes or forced to hit a wall and then spread out, this is possible. If you have created some planet in space and you want to show the blast of the planet by attack of asteroids from asteroid belt then , it is possible .


Example of animated Explosion effect

One can create absolutely any fire effect he wishes. There is another advantage in using this special effect , there are lots of other attributes for this effect like , one can set the intensity of fire ,or one can set the explosion parameters like radius , explosion colour ,
fading colour , also one can create smoke after explosion or combustion takes place .


The combustion and smoke effect together is as shown in the following image .





One can also add gravity effect to exploded material , so that realistic scenes can be created . In actual special effects there are about 70 to 80 % flaws ; but due to such attractive techniques normal person never get noticed of these flaws ,only an expert can notice .
The reason to use this special effect is, manually we cannot create fire or combustion in computer animation and another thing is it is very easy to implement in less time.
The only disadvantage here is that rendering time requirement is very high .So underlying machine should be sufficiently compatible for processing speed ,because due to smoke or explosion complexity of the view drastically increases , due to increase in details.



Fog & Underwater Effects:
To improve realistic vision of user another visual effect helps in creating Fog like environments in the view. There are many types of Fog one can create,
1. Uniform fog
2. Layered fog
3. Turbulence fog
4. Volume fog

In uniform fog, complete view will be covered with the fog. There will be complete uniformness in the view where ever you take your camera.
In layered fog , animator can choose the specific layer in the view above which or below which he wanted to add the fog effect . This is useful in creating the Horizon effect .
For example if animator wanted to create a sea animation he can just add a little amount of fog at the horizon for distinguishing the views .
Turbulence fog is a random type of fog . If animator want a random effect of fog for example fog below the night street lamp , or then this kind of fog is very useful.
Volume fog is very thick kind of fog used to create search lights in combination with Volume lights.


Fog Effect added to a real environment
Using fog effect one can add beautiful clouds while creating environment for sky.

Other advantage of fog effect is that , underwater effects can be created from the same thing. Using Volume light and fog one can create underground environments . Actually these environments are nothing but normal fogs but due to addition of Volume light , viewer experiences an optical illusion and feels that what he is watching is underwater !

Creating underwater effect using fog
An interesting thing about fog effect is one can modify fog for desired view. Like one can increase or lessen density of fog .Also one can decide to what distance fog should present .One can attenuate the fog limits. One can add colour to fog ; for example if animator want to add fog at the time of evening (in view) then one can add blue shade to the fog. Animator can add his own water creatures in it.

Morphing:
Morphing is the process of transforming one image into another. This is one of the favorite special effects in creating advertisements. Morphing is an image processing technique used for the metamorphosis from one image to another. The idea is to get a sequence of intermediate images which when put together with the original images would represent the change from one image to the other. The simplest method of transforming one image into another is to cross-dissolve between them. In this method, the color of each pixel is interpolated over time from the first image value to the corresponding second image value. This is not so effective in suggesting the actual metamorphosis. For morphs between faces, the metamorphosis does not look good if the two faces do not have the same shape approximately
The morph process consists of a warping stage before cross-dissolving so that the two images have the same shape. The warp is specified, in this case, by a mapping between lines in the first and second images.

There are two ways to warp an image. They are

Forward Mapping:

In this method, each pixel in the source image is mapped to an appropriate place in the destination image. Thus, some pixels in the destination image may not be mapped. We need interpolation to determine these pixel values. This mapping was used in our point-morphing algorithm.
Reverse Mapping:
This method goes through each pixel in the destination image and samples an appropriate source image pixel. Thus, all destination image pixels are mapped to some source image pixel. This mapping has been used in the Beier/Neely line-morphing method.

In either case, the problem is to determine the way in which the pixels in one image should be mapped to the pixels in the other image. So, we need to specify how each pixel moves between the two images. This could be done by specifying the mapping for a few important pixels. The motion of the other pixels could be obtained by appropriately extrapolating the information specified for the control pixels. These sets of control pixels can be specified as lines in one image mapping to lines in the other image or points mapping to points.
Point Warping: This method of image warping is based on a forward mapping technique, where each pixel from the input image is mapped to a new position in the output image. Since not every output pixel will be specified, we must use an interpolating function to complete the output image. We specify several control points, which will map exactly to a given location in the output image. The neighboring pixels will move somewhat less than the control point, with the amount of movement specified by a weighting function consisting of two separate components, both dependent on the distance from the pixel to each control point in the image.

A simple fundamental issue is as follows :

first_object final_object

The first object and final object is given animation software .& if we animate the sequence iver some frames then we will get an animation of morphing of initial image into another image .

The following image shows a statue of bald man is morphed into statue of an old and hairy man.




Particle Systems:

Particle systems are used for animating all sort of particles like water drops , sprinkles , magical stars . The term particle system is loosely defined in computer graphics. It has been used to describe modeling techniques, rendering techniques, and even types of animation. In fact, the definition of a particle system seems to depend on the application that it is being used for. The criteria that hold true for all particle systems are the following:

Collection of particles - A particle system is composed of one or more individual particles. Each of these particles has attributes that directly or indirectly effect the behavior of the particle or ultimately how and where the particle is rendered. Often, particles are graphical primitives such as points or lines, but they are not limited to this. Particle systems have also been used to represent complex group dynamics such as flocking birds.
Stochastically defined attributes - The other common characteristic of all particle systems is the introduction of some type of random element. This random element can be used to control the particle attributes such as position, velocity and color. Usually the random element is controlled by some type of predefined stochastic limits, such as bounds, variance, or type of distribution.



Each particle goes through three distinct phases in the particle system: generation, dynamics, and death. These phases are described in more detail here:
Generation - Particles in the system are generated randomly within a predetermined location of the fuzzy object. This space is termed the generation shape of the fuzzy object, and this generation shape may change over time. Each of the above mentioned attribute is given an initial value. These initial values may be fixed or may be determined by a stochastic process.
Particle Dynamics - The attributes of each of the particles may vary over time. For example, the color of a particle in an explosion may get darker as it gets further from the center of the explosion, indicating that it is cooling off. In general, each of the particle attributes can be specified by a parametric equation with time as the parameter. Particle attributes can be functions of both time and other particle attributes. For example, particle position is going to be dependent on previous particle position and velocity as well as time.
Extinction - Each particle has two attributes dealing with length of existence: age and lifetime. Age is the time that the particle has been alive (measured in frames), this value is always initialized to 0 when the particle is created. Lifetime is the maximum amount of time that the particle can live (measured in frames). When the particle age matches it's lifetime it is destroyed.


The above picture shows different types of particle systems . There are spray particles , snow particles, blizzard , PArray ,PCloud , Super Spray particles. The above structure is taken from 3D-StudioMax software .

Lights Effect :

In computer animation ‘Light’ object plays a very important role in creating a feel to viewer that the image on the screen is realistic one. There are many types of lights in animation resembling to real-world lights like,
1. Omni light
2. Spot light
3. Direct light
4. Sun light
5. Volume light

Omni lights are used for creating effect like diffused light, i.e. everywhere in the plane one will find the same light.
Spot lights are used for highlighting specific part of the view. These lights are used to attract user vision to particular region of the perspective view.
Volume lights are special types of lights used in fog like atmosphere. Here one can experience the fog elements in the direction of light. This is one of the best lights used for creating underwater effect.

It is preferable to stick with reality as close as you can, and stylize the lighting only as you need to, to evoke a particular feeling or style. One thing you may be wondering about, besides placement, which was detailed fairly well, is color. What makes a particular color of light "real," and how to choose! Well, this is where you should study a little about color photography. Light is usually cast in a certain color, and even when our eyes adapt to it (making general illumination look white) it remains that color. Film is completely objective, and records the actual color of light, without adapting or performing an "automatic mental white balance." What is important is understanding that all light has a color temperature. For example for a night effect one has to use light with a blue shade. For an exploded site it’s better to use red shaded light.



Here is a standard for choosing the light colour for your view in animation:



This is one of the basic standards used for creating fundamental light effects in animated view.3D-Max has a nice way of visualizing the attenuation of a light. It can also control near attenuation. You will not normally need to use the near attenuation, since it increases the intensity over distance. This happens only in specific occasions, such as when light is being focused through a lens. So usually, you will only need to use the far attenuation, since you will be controlling this specifically the way you want. Often, artists new to lighting wonder how to get highlights to appear on their surfaces, and wonder how light angles affect their scenes. There is a simple rule to remember: the law of reflection. It basically reminds us that the angle of incidence and reflection are equal on a smooth surface. A surface has a surface normal. The normal is a line extending perpendicular to the surface. Thus the normal points in the direction of the face. The angle of incidence is the angle between the light ray and the surface normal. Light will reflect from the surface at an equal angle.

So, if you want to see a highlight, your task is to make light rays bounce from a light source directly into the camera. Position your light so that it strikes you desired surface area at the same angle your camera is positioned to that surface normal. A nice tool in MAX is the place highlight tool. You can choose a specific area of your polygon surface, and max will automatically adjust the position of your light to get a highlight where you want.There is a lot more to creating highlights than just adjusting the light correctly. It helps to subtly curve your surfaces, even if they are supposed to be flat. Displacement maps and bump maps help a lot, too. Material settings are very important too, but this goes into things.

Texture / Mapping:
Using only standard colours one cannot make an effective view .For example if someone is creating a wall from many boxes , he can put boxes on one another.These boxes will have standard library colours . Instead of this , one can use a single box and just apply texture to it . This technique is very easy and fast that conventional one .
Following is the example of Texture effect . These images are created for the 3D game “Quake – 3D “ . The first image shows the battlefield from the game without texture mapping , while the next image shows material applied with texture.


In current softwares like 3D-Studio Max , Maya one can get thousands of texture maps . There are two different types of materials that light can pass through, transparent materials, and translucent materials. As a simple example think of glass. Window glass is transparent, allowing light to pass directly through it, and allowing us to see clearly through it. Frosted glass is translucent; it allows light to pass through, but not clearly enough for us to be able to see through. The reason frosted glass is translucent is because of the way that light gets refracted when it passes through. Refraction is the bending of light as it passes through a material. Refraction can be witnessed by looking at a spoon in a cup of coffee. As light waves pass through the liquid they are slowed down and bent. Since the light waves bend when they pass both into and back out of the liquid the part of the spoon we see below the surface appears bent.


Here is the effect of reflection maps. In the left image water glass is given only opacity map. While in the right image glass is given Reflection map; where one can see the actual reflection of the floor. Here is floor is also given a Checker map. There are many more maps like bump map , diffusion maps , environment maps .
When visualizing the terrain surface and it’s features ,colour and texture are critical .This information is often extracted from photographs or videos or is synthesized from general geographical characteristics . It’s then integrated with the surface information , whether the surface is a grass field , a road , or a structure . when actual data is not available , textures and colours are synthesized and applied to the database. Textures add substantial detail to the visual representation that is not achievable with geometry alone.
Textures or maps are nothing but the images like .jpeg, .avi, .tga, .pict etc.
Applying textures to some object means binding that image to that object.


APPLICATIONS OF ANIMATION IN REAL WORLD:

In comparison to traditional animation, computer animation is still relatively younger, and in the short period of its development has already demonstrated an unlimited potential in a wide number of applications. Moreover, it should not just been seen as another way of creating humorous cartoons, it is a revolutionary approach to simulating and visualizing an animated 3-D world. The ability to construct imaginary world within a computer’s memory seems so fantastic as to be unbelievable.

Advertising:

Advertising is a popular application for computer animation because the projects often provide animators with the opportunity to explore and develop new techniques which they would not normally investigate, The storyboards can call for the modeling of entire kitchen , pianos , detergent box , biscuits , teapots , spinning galaxies .These elements are then animated with inbetweened , moved along curves , composited with live action and video until the client is convinced that the desired message will be communicated to the viewing public. Modelling is still a time – consuming activity especially when objects such as cars, engines , frogs , and landscapes have to be built – it is not just the model’s complexity that causes problem but identifying useful sources of data .

A cold-drink advertisement
Advertising calls for a variety of media to be integrated – in particular , computer animation is often incorporated with images derived from live action . Balancing scale and perspective between the two systems is then very important .Since computer models are of varying dimensions they can be interpreted at any level of scale by adjusting certain parameters
The level of realism is achieved in these sequences is very high ,and sometimes the public are not aware that computers have been used at all !Perhaps all that they aware iof is that they find little difficult to understand hoe the effect was produced .



Film Special Effects :
Films such as ‘Shrek’ , ‘The Final Fantasy’ , ‘Terminator 2’ , have demonstrated that there is a real place for computer animation in creating special effects .Although such models and motion control system have proved to be a cost-effective approach in simulating large alien scenes , computer animation has been very successful in modeling fire , smoke ,explosions , space-craftes , human heads made from water or sand like in ‘Mummy’ .


Matching scale and perspective between synthetic and live images is vital if the effect is to be convincing , and special effect teams go to great lengths to ensure that the final optical or digital composition does not betray the different origins of the images .Even when a film only contains five minutes of computer animation those few minutes are normally action-packed and includes effects that could not been created using a process costing less , otherwise , there would be no point in employing computer graphics . Five minutes at 25 frames / sec requires 7500 images, if these take , on average ,15 minutes to render a total of 1875 hours of rendering time is needed ! But this is only for one rendering of the animation ; it is high likely to be rendered for several times before a director is satisfied with the piece . Therefore a large team of people is required to undertake such projects with a complementary array of workstations.

Modelling plays an important role in this work as storyboards never call for anything as simple as a tumbling a logo or teapot . Itt is more likely to be a humanoid walking through a wall of flames who , imperceptibly , dissolves into a live human over a matter of 2 seconds .Such a sequence requires the humanoid to be accurately modeled to the finest surface detail. It must be animated to walk with a gait identical to the actor’s , and then with the aid of matters , it can be digitally composited with the live action to create a seamless join.



3-D cartoons :
At the begging of 3D graphics era , 3D cartoons sequences are short and are the result of considerable research and dedication to solving complex ploblems . However , as they are resolved , we move closer to the day when a full-lengh 3-D cartoon is [produced using nothing but computer animation .

Meet, the actor from movie “Monsters Inc.”

In recent years, tremendous advances have been made into all sort of areas , from the modelling objects to rendering , today it seems that virtually anything is possible given a budget and sufficient time . Although it is inevitable that computer animation will establish a niche for a variety of graphics styles that have already begun to appear , the traditional cartoon industry will not abandon a life time ‘s work in perfecting a style that is so appealing . Many collaborative projects , demonstrate that it must be possible to develop software that will enable animators to continue their cartoons and also benefit from advantage associated with digital technology.

Scientific Visualization:
In the 20th century , we have witnessed the birth of the PC , the graphics workstations , minicomputers ,and supercomputers .Today the scientific data are not only 3 dimensional in spatial sense but includes attributes of pressure , temperature , velocity ,density . Thus the fundamental problem facing modern scientific visualization is the graphical representation of multi-dimensional data.
Computer animation system are now being used by the scientific community to provide animated visualization of time-dependent datasets . For example , in finite element analysis , where objects are represented within a computer as linked spatial mesh of several tens-of-thousands of nodes . The internal representation can be processed mathematically to compute the stresses , strains , resulting from imaginary forces and torques . When such data is visualized , the simulated structure can be seen to flex , and perhaps even vibrate. Such visual techniques enables the model to be examined from any point of view or trajectory , and rendered with surface details and shadows , even composited with real-world images.

Architecture :
Architects have used 2-D computer graphics as an aid to the layout of floor plans and the organization of service networks such as electricity ,water etc .Today 3-D systems are plating an increasing role in the visualization if interiors and exterior views .
Although architecture seems to be obvious application for computer animation , it must be appreciated that the database representing a large building could store several hundred thousand elements , each of which might have detailed geometry such as a window frame .It is not practical to render this level of details and animate it as though it were a logo .Furthermore , Gouraud or Phong shadings are not realistic shading models for visualizing the interiors illuminated by diffuse light and daylight , and exteriors where the time of the day , weather conditions , reflections and shadows are important to the client .
In spite of some problems , computer animation is being used for visualizing large architectural and under-construction projects , in which iit is difficult to imagine how new buildings and roads will impact upon the existing environment. Arial sequences can provide a dramatic insight into the scale of these projects , and clarify area of confusion created by looking at plan elevations on a drawing .But as a virtual camera can be placed anywhere within database , there is no space for confusion.

Flight Simulation :
Computer animation plays a key role in flight simulators where real-time image generators are used to provide realistic textured images of airports and the surrounding terrains. The pilot’s cockpit , which is working replica of some specific craft effectively becomes the computer’s virtual camera .The pilot’s flying controls feed digital signals direct to a program simulating the flying characteristic of plane. This in turn predicts where the plane will be in a few millisecond’s time and specific position in space with yaw , pitch , and roll angles .
All the virtual environment can be simulated like any weather conditions , or like other plane taking off , and landing at the same time you are flying , the other vehicles on airport, people , the teminal buildings etc . Thus as pilot approaches a scene , the image generator automatically fades the low – detailed model out and fades in the high detailed model . This form of model management ensures that the scene does not contain superfluous polygons , which ultimately affects the rendering time .



Game Development:
The functionality and image quality of today’s interactive games continue to improve along with new visual techniques in animation. Popular techniques like ‘motion –blur’ , ‘ combustion’ , ‘explosions’, ‘motion –capture’ are playing an important role in game development. Today’s softwares like ‘3D-Studio Max’, ‘Maya’,’ Flash’, are ‘Character –Studio’ taking games in new era of realistic visualization .



CLOSING WORDS:
In comparison to traditional animation, computer animation is still relatively younger, and in the short period of its development has already demonstrated an unlimited potential in a wide number of applications. Moreover, it should not just been seen as another way of creating humorous cartoons, it is a revolutionary approach to simulating and visualizing an animated 3-D world. The ability to construct imaginary world within a computer’s memory seems so fantastic as to be unbelievable.


BIBLIOGRPHY:

1. 3D COMPUTERANIMATION - by JOHN VINCE
2. 3D STUDIO MAX R3 BIBLE - by MURDOCK
3. COMPUTER ANIMATION - by NEAL WEINSTOCK
4. COMPUTER GRAPHICS WORLD – FEB.2002 ISSUE
5. INTRODUCTION TO COMPUTER GRAPHICS – by FOLEY, FEINER, HUGHES, PHILLIPS.