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

Array implementation of a queue, Since the stack is list of elements, the q...

Since the stack is list of elements, the queue is also a list of elements. The stack & the queue differ just in the position where the elements may be added or deleted. Similar to

The time and space complexities of an algorihm, Relation between the time a...

Relation between the time and space complexities of an algorithm The examining of algorithm focuses on time complexity and space complexity. As compared to time analysis, the a

Selection sort, how to reduce the number of passes in selection sort

how to reduce the number of passes in selection sort

Postfix expression algorithm, Write an algorithm to calculate a postfix exp...

Write an algorithm to calculate a postfix expression.  Execute your algorithm using the given postfix expression as your input : a b + c d +*f ↑ . T o evaluate a postfix expr

Write down a module to merge two linked lists, Two linked lists are having ...

Two linked lists are having information of the same type in ascending order. Write down a module to merge them to a single linked list that is sorted merge(struct node *p, stru

The various ways in which lc code can be accessed, Problem Your LC code...

Problem Your LC code is stored in a memory location as shown and the variable name is LC                  LC Memory address       Content(LC code)

Breadth first search, While BFS is applied, the vertices of the graph are d...

While BFS is applied, the vertices of the graph are divided into two categories. The vertices, that are visited as part of the search & those vertices that are not visited as part

Depth of complete binary tree, What will be depth do , of complete binary t...

What will be depth do , of complete binary tree of n nodes, where nodes are labelled from 1 to n with root as node and last leaf node as node n

Linear array, representation of linear array

representation of linear array

Algorithm for sorting a deck of cards, What is wrong with the following alg...

What is wrong with the following algorithm for sorting a deck of cards (considering the basic properties of algorithms)? I. Put the cards together into a pile II. For each ca

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