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

Stack, using a program flowchart design a program to illustrate pop and pus...

using a program flowchart design a program to illustrate pop and push operation

Binary search tree bst, Describe Binary Search Tree (BST)? Make a BST for t...

Describe Binary Search Tree (BST)? Make a BST for the given sequence of numbers. 45, 36, 76, 23, 89, 115, 98, 39, 41, 56, 69, 48 Traverse the obtained tree in Preorder, Inord

Relation of time and space complexities of an algorithm, What is complexity...

What is complexity of an algorithm? What is the basic relation between the time and space complexities of an algorithm? Justify your answer by giving an example.

Algorithm that inputs the codes for all items in stock, A shop sells books,...

A shop sells books, magazines and maps. Every item is identified by a unique 4 - digit code. All books have a code which starts with 1, all maps have a code starting with 2 and all

Estimate cost of an optimal diapath, Normally a potential y satisfies y r ...

Normally a potential y satisfies y r = 0 and 0 ³ y w - c vw -y v . Given an integer K³0, define a K-potential to be an array y that satisfies yr = 0 and K ³ y w - c vw -y v

Design a doubly linked list, Instructions : You have to design a dou...

Instructions : You have to design a doubly linked list container. The necessary classes and their declarations are given below The main() function for testing the yo

Define chaining process of hashing, Chaining In this method, instead of...

Chaining In this method, instead of hashing function value as location we use it as an index into an array of pointers. Every pointer access a chain that holds the element havi

Sorting, explain quick sort algorithm

explain quick sort algorithm

Lilz, I need to know about data structure and algorithms. can you help me?

I need to know about data structure and algorithms. can you help me?

Explain the array and linked list implementation of stack, Question 1. ...

Question 1. How can you find out the end of a String? Write an algorithm to find out the substring of a string. 2. Explain the insertion and deletion operation of linked lis

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