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

Flow chart, that will determine the volume of the sphere or the volume of c...

that will determine the volume of the sphere or the volume of cone or volume of pyramid depending on the choice of the user

Function performs multiplication of two numbers, You need to write a functi...

You need to write a function that performs multiplication of two numbers in your data structure. Again, remember how you multiply numbers in base 10 and you should be fine. Multipl

Two broad classes of collision resolution techniques, Two broad classes of ...

Two broad classes of collision resolution techniques are A) open addressing and B) chaining

Write an algorithm inputs speed of cars using pseudocode, Write an algorith...

Write an algorithm by using pseudocode which: Inputs top speeds of 5000 cars Outputs fastest speed and the slowest speed Outputs average speed of all the 5000 cars

Describe commonly used asymptotic notations, Q.1 Compare two functions n 2 ...

Q.1 Compare two functions n 2 and 2 n for various values of n. Determine when second becomes larger than first. Q.2 Why do we use asymptotic notation in the study of algorit

How can a lock object be called in the transaction, How can a lock object b...

How can a lock object be called in the transaction? By calling Enqueue and Dequeue in the transaction.

Define minimum spanning tree, Define Minimum Spanning Tree A minimum sp...

Define Minimum Spanning Tree A minimum spanning tree of a weighted linked graph is its spanning tree of the smallest weight, where the weight of a tree is explained as the sum

An undirected graph g with n vertices and e edges, An undirected graph G wi...

An undirected graph G with n vertices and e edges is shown by adjacency list.  What is the time required to generate all the connected components? O (e+n)

Give example of assertion and abstract data type, Give example of assertion...

Give example of assertion and abstract data type For illustration, consider Natural ADT whose carrier set is the set of non-negative integers and whose operations are the usual

Algorithm for pre-order traversal, Hear is given a set of input representin...

Hear is given a set of input representing the nodes of a binary tree, write a non recursive algorithm that must be able to give the output in three traversal orders. Write down an

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