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

Draw the process flow diagram, Draw the process flow diagram: Anand   ...

Draw the process flow diagram: Anand   Dairy (AD) sources 150,000 litres of milk daily from large number of local villagers .The milk is collected from 4:00 AM to 6:00 am and

Linear array - numerical, Q. A linear array A is given with lower bound as ...

Q. A linear array A is given with lower bound as 1. If address of A[25] is 375 and A[30] is 390, then find address of A[16].

Define the term - array, Define the term - Array A fixed length, ord...

Define the term - Array A fixed length, ordered collection of values of same type stored in contiguous memory locations; collection may be ordered in several dimensions.

Circular linked list, In a circular linked list There is no beginning a...

In a circular linked list There is no beginning and no end.

Design a binary tree, (a) Suppose that t is a binary tree of integers (that...

(a) Suppose that t is a binary tree of integers (that is, an object of type BinTree of Int.) in the state shown in Figure 3.   Give the vectors returned by each of the f

Definitions of graph, A graph G might be defined as a finite set V of verti...

A graph G might be defined as a finite set V of vertices & a set E of edges (pair of connected vertices). The notation utilized is as follows: Graph G = (V, E) Consider the g

Two sparce matrices multipilcation algorithm, Write an algorithm for multi...

Write an algorithm for multiplication of two sparse matrices using Linked Lists.

Explain the prim''s minimum spanning tree algorithm, Question 1. Explai...

Question 1. Explain the different types of traversal on binary tree 2. Explain the Prim's minimum spanning tree algorithm 3. Differentiate fixed and variable storage allo

Define a sparse metrics, Define a sparse metrics. A matrix in which num...

Define a sparse metrics. A matrix in which number of zero entries are much higher than the number of non zero entries is known as sparse matrix. The natural method of showing m

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