Exploring-the-World-of-Computer-Graphics_unit_1&2.pptx

Computer Graphics is the field of study and technology that deals with creating, manipulating, and displaying visual images using computers. It involves generating images ranging from simple 2D drawings to complex 3D models and animations. Applications of computer graphics include video games, simulations, virtual reality, graphic design, movies, and user interfaces. Gaming refers to the creation, design, and playing of video games—interactive digital entertainment that involves players controlling characters or environments to achieve specific goals. It combines storytelling, graphics, sound, and user interaction to deliver engaging experiences across various platforms like consoles, PCs, and mobile devices. Gaming also includes competitive esports and social gaming communities.

1. COMPUTER GRAPHICS AND GAMING BY : MS. GAURI BHELONDE

2. Computer Graphics Remembering: To acquaint the learner with the basic concepts of Computer Graphics. Understanding: To learn the various algorithms for generating and rendering graphical figures. Applying: To get familiar with mathematics behind the graphical transformations. Understanding: To understand and apply various methods and techniques regarding projections, animation, shading, illumination and lighting. Creating: To generate Interactive graphics using OpenGL.

3. What is Computer Graphics? Computer graphics is the art and science of creating, manipulating, and representing visual data using computers. It encompasses everything from simple lines and shapes to complex 3D environments and realistic animations. Core Components Modeling: Defining the geometric shape of objects. Rendering: Generating an image from a model. Animation: Depicting movement over time. Display: Presenting the visual output to the user. Interdisciplinary Foundations Mathematics: Geometry, linear algebra, calculus. Programming: C++, Python, OpenGL for implementation. Physics: Light interaction, motion dynamics. Key technologies like rasterization and ray tracing are fundamental to how GPUs process and render visual information.

4. Evolution of Computer Graphics Computer graphics has come a long way since its inception, evolving from simple vector lines to photorealistic virtual worlds. 1 1960s Vector Graphics: Early systems like Sketchpad pioneered interactive drawing and CAD. 2 1980s-90s CGI Revolution: Pixar and major film studios integrate CGI into blockbusters, pushing realistic rendering. 3 2000s+ Real-time Rendering: Advances in GPUs drive realistic graphics in gaming and interactive applications. 4 Present Day Emerging Tech: AR/VR, 3D web, and AI-assisted graphics redefine visual experiences.

5. Diverse Applications of Computer Graphics Computer graphics is integral to numerous fields, transforming industries and enhancing human interaction with digital information. Scientific Visualization Displaying complex data, from climate models to molecular structures, for analysis. CAD (Computer-Aided Design) Designing and engineering products, architecture, and machinery. Entertainment Creating immersive worlds for movies, video games, and visual effects. Medical Imaging Visualizing anatomical structures for diagnosis and surgical planning. GUI Development Designing intuitive graphical user interfaces for software and systems. Education & Training Developing interactive learning platforms and realistic simulators.

6. Scientific Visualization

7. Entertainment: Focus on interactivity, Cost effective solutions, Avoiding computations and other tricks

8. Multimedia Applications Multimedia in computer graphics refers to the integration of various forms of content, including text, images, audio, animation, and video, to create rich interactive experiences. These applications span across various domains, from immersive gaming experiences to engaging e-learning platforms, interactive AR/VR environments, and dynamic digital advertising campaigns.

9. CAD-Computer Aided Design Used in design of buildings, automobiles, aircraft, watercraft, spacecraft, computers, textiles & many other products Objects are displayed in wire frame outline form Software packages provide multi-window environment

10. Graphics design package provides standard shapes (useful for repeated placements) Animations are also used in CAD applications Realistic displays of architectural design permits simulated “walk” through the rooms (virtual -reality systems)

11. Medical Imaging To apply image processing methods Digitize a photograph (or picture) into an image file Apply digital methods to rearrange picture parts to enhance color separations Improve quality of shading Tomography – technique of X-ray photography that allows cross-sectional views of physiological systems to be displayed Computed X-ray tomography (CT) and positron emission tomography ( PET) use projection methods to reconstruct cross sections from digital data Computer-Aided Surgery is a medical application technique to model and study physical functions to design artificial limbs and to plan & practice surgery

12. Education and Training Simulation and Modeling Simulation in computer graphics involves creating virtual representations of real-world systems, allowing for interactive exploration and analysis. Flight Simulators Realistic training environments for pilots, replicating aircraft controls and flight conditions. Weather Models Visualizing complex atmospheric phenomena and predicting weather patterns. Surgery Training Virtual reality simulations for medical students to practice surgical procedures. The importance of simulation lies in its ability to provide real-time interaction and physics-based visualization, offering safe and effective training or analysis in various critical fields.

13. Flight Simulator Weather Forecast VR for medical surgery training

14. Major component – Window manager (multiple-window areas) To make a particular window active, click in that window (using an interactive pointing device) Interfaces display – menus & icons Icons – graphical symbol designed to look like the processing option it represents Advantages of icons – less screen space, easily understood Menus contain lists of textual descriptions & icons GUI Development

15. Design and Drawing in Graphics Design and drawing are foundational elements in computer graphics, enabling the creation of both functional and aesthetic visual content. Design Principles Graphic Design: Focuses on visual communication for user interfaces, icons, and branding elements. Tools like Adobe Illustrator are widely used. Industrial Design: Involves modeling and engineering products for manufacturing, often utilizing CAD software like AutoCAD. Digital Drawing Techniques Digital drawing employs mathematical representations of lines and curves, such as Bezier and B-splines, to create scalable and editable artwork. Sketching and Drafting: Software tools replicate traditional sketching and drafting processes, allowing for precision and iteration.

16. Bringing Movement to Life: Animation Animation in computer graphics transforms static images into dynamic sequences, creating the illusion of motion. 2D Animation Traditional cel animation techniques adapted for digital platforms, commonly seen in Flash animations and anime. 3D Animation Creating three-dimensional models that can be posed and moved in a virtual space, utilizing software like Maya and Blender. Motion Capture Recording real-time movements from actors and applying them to digital characters, enhancing realism and efficiency. Core concepts include keyframes (defining critical poses), tweening (generating in-between frames), rigging (creating digital skeletons), and skinning (attaching mesh to the skeleton).

17. How Are Pictures Stored and Displayed? Understanding how digital images are stored and displayed is crucial for computer graphics professionals. Image Storage Types Raster Images: Composed of a grid of pixels (e.g., BMP, JPEG, PNG). Resolution-dependent. Vector Images: Defined by mathematical paths and shapes (e.g., SVG, PDF). Scalable without loss of quality. Color Models RGB (Red, Green, Blue): Additive color model for displays. CMYK (Cyan, Magenta, Yellow, Black): Subtractive color model for printing. HSL (Hue, Saturation, Lightness): Intuitive color model for designers. Displaying Images: The Graphics Pipeline The Graphics Pipeline is a conceptual model that describes the steps involved in rendering 3D graphics to a 2D screen. Frame Buffer: A dedicated memory area that stores the pixel data to be displayed on the screen. Display Features: Include refresh rate (how often the image is updated) and scan conversion (converting geometric shapes into pixels).

18. Pixel(Picture element (pel)) :- smallest addressable screen element of an image or a dot that can be manipulated. Resolution:- number of pixels a screen can display within a given area or pixels per inch. e.g. 800 x 600, 640 x 480 Aspect ratio:- ratio of vertical points to horizontal points to produce equal length lines in both directions on the screen. e.g. 4:3, 8:5, 16:10 Frame buffer (Refresh buffer) • Large contiguous piece of computer memory • This memory area holds the set of intensity values for all the screen points • Retrieved and painted on the screen • Bi-level system:- ‘ON’ – 1 ‘OFF’ - 0 • High quality system uses 24 bits per pixel • Frame buffer storage depends on resolution: 1. Bitmap :- on black and white system with one bit per pixel the frame buffer is commonly called bitmap 2. Pixmap :- Systems with multiple bits per pixel the frame buffer is often referred to as a pixmap

19. Rasterization and Scan conversion • Rasterization :- The process of determining the appropriate pixels for representing picture • Scan conversion :- The process of representing continuous picture as a collection of pixels

20. Challenges in Displaying Pictures Despite rapid advancements, displaying high-quality computer graphics still presents several technical challenges. Resolution & Scaling Maintaining visual fidelity across various display sizes and pixel densities. Color Consistency Ensuring colors appear uniform and accurate across different devices and lighting conditions. Latency & Delays Minimizing the time lag between user input and visual response, crucial for interactive applications. Hardware Limitations Dealing with the computational power and memory constraints of GPUs and other display hardware. Visual Artifacts Addressing issues like aliasing (jagged edges), tearing (misaligned frames), flickering, and compression artifacts.

21. Cathode Ray Tube https://youtube.com/shorts/cvqWS3IQRiU?feature=shared

22. Vector Scan Display RANDOM SCAN DISPLAY CALLIGRAPHIC DISPLAY STROKE WRITING DISPLAY Vector Scan is a technique used for producing Images on the screen. Beam is directed to the area on the screen where picture is to be drawn. The display Buffer Memory stores the “ Display List ” which contains point and line plotting commands with (x,y) or (x,y,z) coordinates as well as Character Plotting Commands. Display Controller interprets this command and help Beam-Deflection Circuit to display E’ Beam writing on CRT’s phosphor coating. The phosphor light decays after few milliseconds so: we need to refresh phosphor at least 30-60 times per second . Advantages: Higher Resolution than Raster Scan Display Produces smooth lines Need less memory to store picture definition. Disadvantages: Can't draw realistic images Limitation on colors to be displayed eg:max-4 colors depends how deep beam penetrates Architecture of Vector Scan Display

23. Raster Scan Display The displayed image is stored in the form of 0’s and 1’s in the refresh buffer. The video controller reads the refresh buffer and produces the actual image on the screen. It does this by scanning one scan line at a time, from top to bottom and then back to the top. FRAME BUFFER HOLDS THE INTENSITY VALUE OF PIXEL. https://youtu.be/-6Odk9RXVtA?si=TPVF8InWKtRzmJ2X

24. The Normal CRT can generate images of single color due to limitation of phosphor coating. It generates a range of colors by combining the emitted light from multilayered phosphor coated color CRT. There are basic 2 techniques used for producing color display: a) Beam - Penetration technique b) Shadow mask technique Beam penetration technique is used with Random Scan display where CRT is coated with 2 layers of colors usually Red and Green. OUTER LAYER- RED PHOSPHOR AND INNER LAYER- GREEN PHOSPHOR Color depends on how far the e- beam penetrates into the phosphor layers. Low e- beam speed strike only the red phosphor, thus produces red traces on the screen. High e- beam penetrates into green phosphor and produces green traces. Medium e- beam produces colors of combination of red and green like orange/ yellow etc merits : Inexpensive demerits: only 4 color and its not of good quality. Beam Penetration Technique

25. Shadow Mask Technique Used in Raster Scan Display and produces wide range of colour. 3 Phosphor dots of Red , Green and Blue at each pixel position, emits corresponding colour. 3 e - beam , one for each colour and shadow mask grid just phosphor coated screen. Shadow mask grid consists holes align with dot patterns 3 e - beam are deflected and focused as a group on shadow mask and excite a dot by passing hole 1 beam can activate only 1 color and colour generated by combination of 3 colours by varying intensity more colors are produced.

26. Direct View Storage Tube

27. Contains a gas at low pressure sandwiched between horizontal and vertical grids of fine wires A large voltage difference will cause the gas to glow Very durable Used for military applications, PLATO educational system Plasma Panel Display

28. https://youtu.be/96QwqOZ4xjE?feature=shared https://youtu.be/Gx-JVoOFYhs?feature=shared LCD Display Flat panel display technology Lighter in weight due to low voltage and power requirements Light is either transmitted or blocked, depending on the orientation of molecules Electric signal can be used to change molecular orientation LCD Layered Diagram https://youtu.be/yxygknX1AiE?si=XlJt0yermUjMhFRH

29. Open Graphics Library (OpenGL) is a cross-language (language independent), cross-platform (platform-independent) API for rendering 2D and 3D Vector Graphics(use of polygons to represent image). OpenGL API is designed mostly in hardware. Design : This API is defined as a set of functions which may be called by the client program. Although functions are similar to those of C language but it is language independent. Development : It is an evolving API and Khronos Group regularly releases its new version having some extended feature compare to previous one. GPU vendors may also provide some additional functionality in the form of extension. Associated Libraries : The earliest version is released with a companion library called OpenGL utility library. But since OpenGL is quite a complex process. So in order to make it easier other library such as OpenGL Utility Toolkit is added which is later superseded by freeglut. Later included library were GLEE, GLEW, and gliding. Implementation : Mesa 3D is an open source implementation of OpenGL. It can do pure software rendering and it may also use hardware acceleration on BSD, Linux, and other platforms by taking advantage of Direct Rendering Infrastructure. OPEN GL

30. ABSTRACTION GLUT: Windowing toolkit (Key, Mouse Handler, Window Events) GLU: Viewing: Perspective/ Orthographic Image Scaling , Polygon Tessellation Sphere, Cylinders, Quadrilateral Surfaces GL:: Primitives: Point, line, Polygon Shading and Color Translation, Rotating and Scaling Viewing, Clipping, Texture Hidden Surface Removal

31. Install OpenGL on Ubuntu For installing OpenGL on Ubuntu, just execute the following command (like installing any other thing) in terminal : sudo apt-get install freeglut3-dev For working on Ubuntu operating system: gcc filename.c -lGL -lGLU -lglut where filename.c is the name of the file with which this program is saved. Installation and working

32. OpenGL Drawing Primitives OpenGL supports several basic primitive types, including points, lines, quadrilaterals, and general polygons. All of these primitives are specified using a sequence of vertices. Provides a library of functions create pictures Primitive (Graphics output primitive) Geometric primitive Output primitive Primitives Point :- GL_POINTS To state coordinate values for single position glVertex* ( ); e.g. glBegin(GL_POINTS); glVertex(); glEnd();

33. Coordinate position can be 2,3 or 4 dimensions In 4 dimension the fourth dimension is scaling factor Dimensions are specified by first suffix e.g. glVertex 2 glVertex 3 Second suffix code is used to specify data type i (integer) s (short) f (float) d (double) e.g. glBegin(GL_POINTS); glVertex2i(50,100); glVertex2i(75,150); glVertex2i(100, 200); glEnd(); We can specify the coordinate values using array 3 rd suffix code for array is v (vertex) e.g. float point1 [ ]={50.89,100.60,45.89}; float point2 [ ]={-75.66,150.33,188.77}; float point3 [ ]={100.46,200.15,78.78}; glBegin(GL_POINTS); glVertex3fv(point1); glVertex3fv(point2); glVertex3fv(point3); glEnd(); The following code fragment illustrates an example of how the primitive type is specified and how the sequence of vertices are passed to OpenGL. It assumes that a window has already been opened and that an appropriate 2D coordinate system has already been established. // draw several isolated points GLfloat pt[2] = {3.0, 4.0}; glBegin(GL_POINTS); glVertex2f(1.0, 2.0); // x=1, y=2 glVertex2f(2.0, 3.0); // x=2, y=3 glVertex2fv(pt); // x=3, y=4 glVertex2i(4,5); // x=4, y=5 glEnd();

34. Attributes :- a parameter that affects the way a primitive is to be displayed color and size, determine the fundamental characteristics of a primitive special-condition attributes are the options such as visibility or detectability state system or state machine :- graphics system that maintains a list for the current values of attributes and other parameters state variables or state parameters :- Attributes of output primitives and some other parameters, such as the current frame-buffer position Attributes

35. Feature Raster Scan Display Random Scan Display Basic Principle Electron beam scans the screen line-by-line from top to bottom. Electron beam is directed only to the parts of the screen where the image is to be drawn. Drawing Method Works pixel-by-pixel (frame buffer). Works vector-by-vector (stroke drawing). Image Storage Image data stored in frame buffer . Image data stored as a set of line drawing commands in display file. Resolution Fixed resolution determined by pixel density. Resolution depends on the system’s vector generating capability. Refresh Rate Refreshes the entire screen regardless of image complexity. Refreshes only the lines and shapes that are drawn. Complexity Handling Handles complex images like photographs and filled areas well. Best suited for simple line drawings and wireframes. Cost Cheaper to implement. More expensive due to precision electronics. Example Devices Modern monitors, TVs (CRT, LCD, LED). Oscilloscopes, older CAD/CAM displays.

36. Feature Beam Penetration CRT Shadow-Mask CRT Color Production Method Uses 2–4 layers of phosphor coating; color depends on beam penetration depth and energy. Uses three electron guns (Red, Green, Blue) and a shadow mask to direct beams to respective colored phosphor dots. Number of Colors Limited to a few colors (typically red, green, orange, yellow). Can produce millions of colors by mixing varying intensities of RGB. Color Control Beam acceleration voltage determines which phosphor layer glows. Controlled by varying intensities of the three electron beams. Image Quality Lower quality, less accurate colors. High-quality images with precise color reproduction. Cost Cheaper to manufacture. More expensive due to complex structure. Applications Used in older vector graphics terminals. Used in color TVs, computer monitors, high-quality displays.

37. Aspect Animation Simulation Purpose To create the illusion of movement or visual changes over time, often for entertainment or visual communication. To imitate or replicate real-world processes or systems for study, training, or analysis. Nature Focuses on visuals and storytelling, not necessarily bound by real-world laws. Based on mathematical models, physical laws, and real-world behavior. Interactivity Usually non-interactive (pre-rendered sequences). Often interactive, allowing user input to change outcomes. Applications Movies, cartoons, video games, advertising, 3D visual effects. Flight simulators, weather prediction systems, medical procedure training, engineering tests. Example Animated short film showing a bouncing ball. Flight simulator training a pilot with realistic cockpit and controls.

38. Aspect 2D Transformations 3D Transformations Definition Operations applied to objects in a two-dimensional plane (X, Y axes). Operations applied to objects in three-dimensional space (X, Y, Z axes). Axes Involved X-axis and Y-axis only. X-axis, Y-axis, and Z-axis. Basic Types Translation, Rotation, Scaling, Reflection, Shearing (in 2D). Translation, Rotation, Scaling, Reflection, Shearing (in 3D) — extended with depth operations. Rotation Rotation occurs around the origin or any fixed point in the XY plane. Rotation occurs around X-axis, Y-axis, or Z-axis, or around an arbitrary 3D axis. Matrix Representation Uses 3×3 homogeneous matrices for transformations. Uses 4×4 homogeneous matrices for transformations. Applications 2D game graphics, logo design, flat diagrams, and charts. 3D modeling, CAD/CAM design, VR/AR environments, 3D animation. Example Moving a triangle in a 2D coordinate grid. Rotating a cube in 3D space.