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

Life science, Define neotaxonomy. Discuss how electron microscopy can help ...

Define neotaxonomy. Discuss how electron microscopy can help in solving a zoological problem faced by taxonomist.

Process of analysis, The objective analysis of an algorithm is to determine...

The objective analysis of an algorithm is to determine its efficiency. Efficiency is based on the resources which are used by the algorithm. For instance, CPU utilization (Ti

Minimum cost spanning trees, A spanning tree of any graph is only a subgrap...

A spanning tree of any graph is only a subgraph that keeps all the vertices and is a tree (having no cycle). A graph might have many spanning trees. Figure: A Graph

Determine the stereo vision, Determine the stereo vision There is still...

Determine the stereo vision There is still one more major item missing, before we can look at a computer display or plot and perceive it just as we see a real object, namely th

Applications of shortest path algorithms, The minimum cost spanning tree ha...

The minimum cost spanning tree has broad applications in distinct fields. It represents several complicated real world problems such as: 1. Minimum distance for travelling all o

The space - time trade off, The best algorithm to solve a given problem is ...

The best algorithm to solve a given problem is one that requires less space in memory and takes less time to complete its execution. But in practice it is not always possible to

Explain about hubs, Hubs - In reality a multiport repeater - Connect...

Hubs - In reality a multiport repeater - Connects stations in a physical star topology - As well may create multiple levels of hierarchy to remove length limitation of 10

Sorting, Retrieval of information is made simpler when it is stored into so...

Retrieval of information is made simpler when it is stored into some predefined order. Therefore, Sorting is a very important computer application activity. Several sorting algorit

Stack, Explain in detail the algorithmic implementation of multiple stacks....

Explain in detail the algorithmic implementation of multiple stacks.

Header linked list, creation,insertion,deletion of header linked list using...

creation,insertion,deletion of header linked list using c.

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