Important Short Questions and Answers: Three Dimensional Computer Graphics

1. What is color model?

A color model is a method for explaining the properties or behavior of color within some context.

2,List out the properties that are perceive in a light source. Hue

Brightness(luminance)

Purity(saturation)

3.How is the color expressed in XYZ color model? Any color is expressed as C1=XX+YY+ZZ

X,Y, and Z represent vectors in 3D

X,Y, and Z designate the amounts of the standard primaries.

4.What is RGB color model?

The RGB color model is an additive color model in which red,green and blue light is added together in various ways to reproduce a broad array of colors.

5.How is RGB model represented?

RGB model is represented by a unit cube. The color is expressed as an RGB triplet, each component of which can vary from 0 to 1

6.What is YIQ color model?

YIQ is the color space used by the National Television System Committee color TV system. It was designed to separate chrominance from luminance. The Y,I,Q components are assumed to be in the [0,1] or [0,255] range.

7.How is RGB converted to CMY?

The conversion from RGB to CMY representation is done using the following matrix transformation.

[C M Y]=[1 1 1]-[R G B]

Where [1 1 1]represents white.

8.How is CMY converted to RGB?

The conversion from CMY toRGB representation is done using the following matrix transformation.

[R G B]=[1 1 1]-[C M Y]

Where [1 1 1] represents black.

9.What is HSV color model?

HSV stands for Hue,Saturation and Value. Hue-The color we see(red,green,purple) Saturation-How far is the color from gray Values(Luminance)-How bright is the color.

10.What does Computer animation refer?

Computer animation refers to any time sequence of visual changes inscene. It display time variations in object size,color,transparency & surface texture.

11.What is Frame-by-Frame animation?

Frame-by-Frame animation is an animation in which each frame of the scene is separately generated and stored.

12.What does story board define?

The story board is an outline of the action. It defines the motion sequence as a set of basic events that are to take place.

13.What is Graphics editor?

The graphics editor allows designing and modifying object shapes, using spline surfaces, constructive solid geometry methods,or other representation schemes.

14.What is Morphing?

Transformation of object shapes from one form to another is called morphing.

15.What is OPENGL?

OpenGL stands for Open graphics library. OpenGL provides a set of commands to render a 3D scene i.e., the data is provided in an OpenGL usable form and OpenGL will show this data on the screen.

16.Write down the Skeleton of an event driven program using OpenGL? Void main()

{

Initialize things

Set the display mode

Create a screen window

Register the call back functions

Perhaps initialize other things

Enter the unending main loop

}

17.Give the format OpenGL vertex command? The OpenGL vertex command

contains

The prefix “gl” indicates a function from the OpenGL library.

The basic command root

The number of arguments being sent to the function

The type of argument.

18.What is the use of glPointSize()?

The glPointSize() is used to set the size of a point which takes one floating point argument.

Syntax

glPointSize(Glfloat size)

where

size specifies the diameter of rasterized points the default is 1.0

19.What is the Modelview Matrix?

The modelview matrix is the CT. It combines the following 2 effects

Modelling tranformations on objects

the transformation that orients and positions the camera in space.

20.What is the Viewport Matrix?

The viewport matrix maps the standard cube into a 3D viewport

Whose x and y values extend across the viewport and whose z component extends from 0 to 1.