State warnock algorithm, Data Structure & Algorithms

Assignment Help:

Warnock's Algorithm

An interesting approach to the hidden-surface problem was presented by Warnock. His method does not try to decide exactly what is happening in the scene but rather just tries to get the display right. As the resolution of the display increases, the amount of work which the algorithm must do to get the scene right also increases, (this is also true for scan-line algorithms). The algorithm divides the screen up into sample areas. In some sample areas it will be easy to decide what to do. If there are no faces within the area, then it is left blank. If the nearest polygon completely covers it, then it can be filled in with the colour of that polygon. If neither of these conditions holds, then the algorithm subdivides the sample area into smaller sample areas and considers each of them in turn. This process is repeated as needed. It stops when the sample area satisfies one of the two simple cases or when the sample area is only a single pixel (which can be given the colour of the foremost polygon). The process can also be allowed to continue to half or quarter pixel-sized sample areas, whose colour may be average over a pixel to provide antialiasing.  

The test for whether a polygon surrounds or is disjoint from the sample area is much like a clipping test to see if the polygon sides cross the sample-area boundaries. Actually the minimax test can be employed to identify many of the disjoint polygons. A simple test for whether a polygon is in front of another is a comparison of the z coordinates of the polygon planes at the corners of the sample area. At each subdivision, information learned in the previous test can be used to simplify the problem. Polygons which are disjoint from the tested sample area will also be disjoint from all of the sub-areas and do not need further testing. Likewise, a polygon which surrounds the sample area will also surround the sub-areas.

 


Related Discussions:- State warnock algorithm

Write down any four applications of queues, Write down any four application...

Write down any four applications of queues.            Application of Queue (i)  Queue is used in time sharing system in which programs with the similar priority form a queu

Explain the concept of colouring, Colouring The use of colours in CAD/C...

Colouring The use of colours in CAD/CAM has two main objectives : facilitate creating geometry and display images. Colours can be used in geometric construction. In this case,

Explain avl tree, AVL tree An AVL tree is a binary search tree in which...

AVL tree An AVL tree is a binary search tree in which the height of the left and right subtree of the root vary by at most 1 and in which the left and right subtrees are again

STACK, WHAT IS THE PURPOSE OF STACK IN C

WHAT IS THE PURPOSE OF STACK IN C

Explain the linked list implementation of stack, Question 1 Explain the fo...

Question 1 Explain the following? Arrays Stack Trees Question 2 Explain the Linked list implementation of stack Question 3 What is a binary tree? Expla

Applications in file systems of avl trees, 1. In computer science, a classi...

1. In computer science, a classic problem is how to dynamically store information so as to let for quick look up. This searching problem arises frequently in dictionaries, symbol t

Explain time complexity, Time Complexity, Big O notation The amount of ...

Time Complexity, Big O notation The amount of time needed by an algorithm to run to its completion is referred as time complexity. The asymptotic running time of an algorithm i

ALGORITHM AND TRACING, WRITE AN ALGORITHM TO CONVERT PARENTHIZED INFIX TO P...

WRITE AN ALGORITHM TO CONVERT PARENTHIZED INFIX TO POSTFIX FORM ALSO TRACE ALG ON ((A+B)*C-(D-E)$F+G)

Define the external path length, Define the External Path Length The Ex...

Define the External Path Length The External Path Length E of an extended binary tree is explained as the sum of the lengths of the paths - taken over all external nodes- from

Algorithm for a function that takes in integer as argument, Write a detaile...

Write a detailed description of a function that takes in an integer as an argument, then prints out the squares of all positive integers whose squares are less than the input. (The

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd