Computer Graphics- Practice Questions with Verified Solutions Latest Version (Solved 100%)

Computer Graphics- Practice Questions with Verified Solutions Latest Version (Solved 100%) Vector - Answers A value that has a direction and a magnitude (length). Plain numbers can be called "scalars" to explicitly distinguish them from vectors. 2D Graphics - Answers Displayed representation of a scene or an object along two axes of reference: height and width (x and y). 3D Graphics - Answers Displayed representation of a scene or an object that appears to have three axes of reference: height, width, and depth (x, y, and z). 2D display controller - Answers A type of display controller that is intended for 2D operations, like windows, popup menus, text, etc. This kind of display controller can usually not interpolate color values within a primitive, and therefore lacks support for 3D drawing. 3D transform - Answers The act of converting the coordinates of a point, vector, etc., from one coordinate space to another. The term can also refer collectively to the numbers used to describe the mapping of one space on another, which are also called a "3D transformation matrix." OpenGL - Answers A graphics API that was originally developed by Silicon Graphics, Inc. (SGI) for use on professional graphics workstations. OpenGL subsequently grew to be the standard API for CAD and scientific applications and today is popular for consumer applications such as PC games as well. OpenGL ES is the version for embedded systems. Pixel - Answers Shortform for 'picture element'. A pixel is the smallest element of a graphics display or the smallest element of a rendered image. Rendering - Answers The process of creating life-like images on a screen using mathematical models and formulas to add shading, color, and lamination to a 2D or 3D wireframe. Hence: Rendering Engine - the part of the graphics engine that draws 3D primitives, usually triangles or other simple polygons. In most implementations, the rendering engine is responsible for interpolation of edges and 'filling in' the triangle. 2 1/2 D display controller - Answers A 2D display controller that is able to perform the 2D operations required to display 3D primitives. This usually means color interpolation and Z buffering. 3D display controller - Answers A type of display controller that fully supports 3D operations and primitives. At a minimum, such a display controller can accept a 3D triangle, apply a 3D transform, perform the apparent color determination at the vertices, project it onto the 2D bitmap, and draw it with hidden surfaces suppressed. Today's 3D display controllers use the Z buffer algorithm for hidden surface suppression. 3D texture - Answers A texture map that is a function of three variables. This is also called a "solid texture", because the texture map is a volume. Solid textures have been used in diffuse color texture mapping to simulate things like marble and wood grain. Sometimes specifying the color in a volume is simpler than specifying it on the surface of an object, especially if the object has a complex shape. 3D transform - Answers The act of converting the coordinates of a point, vector, etc., from one coordinate space to another. The term can also refer collectively to the numbers used to describe the mapping of one space on another, which are also called a "3D transformation matrix." Adaptive space subdivision - Answers Space subdivision refers to the process of breaking up the scene space into many small regions. Adaptive means this is only done where and when needed, instead of in a fixed way up front. Adaptive space subdivision is often used by ray tracers. Octrees and BSP trees are examples of subdivision algorithms that can be adaptive. Aliasing - Answers The phenomenon that makes smooth lines and edges appear stair stepped or jagged. Aliasing is also called the "jaggies". Alpha buffer - Answers The collective name for the alpha values for every pixel of an image or bitmap. Alpha buffered rendering - Answers Using an alpha buffer for rendering, as opposed to for image compositing or matting. Alpha buffered rendering implies the ability to render semi-transparent primitives. Alpha buffering - Answers The process of rendering or compositing images using an alpha buffer. An alpha buffer supplies an opacity fraction for every pixel. Alpha value - Answers The alpha buffer value for a single pixel. An alpha value is a value indicating the pixels opacity. Zero usually represents totally transparent (invisible) and the maximum value represents completely opaque. Alpha values are commonly represented in 8 bits, in which case transparent to opaque ranges from 0 to 255. AND operator - Answers A constructive solid geometry (CSG) modeling operation on two objects. The resulting object exists only where both input objects existed. This operation is also call INTERSECTION. GIF - Answers A file format for storing images. GIF stands for Graphics Interchange format, and is owned by Compuserve, Inc. MPEG - Answers A lossy image file compression technique for motion pictures or animation sequences. JPEG - Answers A lossy image file compression technique for still images. Palette image format - Answers A format for storing an image that works much like pseudo color in a display controller. Each pixel contains a color ID instead of the actual color value. The true color represented by each color ID is defined in a table called the palette, which must also be stored with the image. A palette is much like a LUT in a pseudo color display controller. Bitmap - Answers The collective name for all the stored pixels in a display controller. The bitmap is also the interface between the display controller's drawing front end and its video back end. The term bitmap is also used in general to refer to any 2D array of pixels. 3D Graphics - Answers Displayed representation of a scene or an object that appears to have three axes of reference: height, width, and depth (x, y, and z). 3D Pipeline - Answers The process of 3D graphics can be divided into three-stages: tessellation, geometry, and rendering. In the tessellation stage, a described model of an object is created, and the object is then converted to a set of polygons. The geometry stage includes transformation, lighting, and setup. The rendering stage, which is critical for 3D image quality, creates a two dimensional display from the polygons created in the geometry stage. Alpha Buffer / Alpha - Answers Channel / Alpha Plane An extra Color channel to hold transparency information; pixels become quad values (RGBA). In a 32-bit frame buffer there are 24 bits of color, 8 each for red, green, and blue, along with an 8-bit alpha channel. Ambient Light - Answers A global level of artificial illumination that ensures all surfaces are visibly lit, particularly those without direct illumination. It functions by representing infinite diffuse reflections from all surfaces within a scene. Animation - Answers A technique providing the illusion of movement using a sequence of (rendered) still images. Anti-aliasing - Answers Anti-aliasing is sub pixel interpolation, a technique that reduces the jagged effect of edges and makes them appear to have better resolution. Application Programming Interface (API) - Answers A standardised programming interface allowing developers to write their applications to a standard and without specific knowledge of hardware implementations. The software driver for the hardware intercepts the API instructions and translates them into specific instructions tailored to specific hardware. The Fujitsu graphics controllers API includes all functions supported in hardware and allows to port software from Cremson up to Carmine family easily. Atmospheric Effect - Answers Effects, such as fog and depth cueing that improve the rendering of real-world environments. Bilinear Filtering - Answers Bilinear filtering is a method of anti-aliasing texture maps. A texture-aliening artifact occurs due to sampling on a finite pixel grid. Point-sampled telexes jump from