Cases of the sutherland hodgman polygon clipping algorithm, Computer Graphics

Assignment Help:

Cases of the Sutherland Hodgman Polygon Clipping Algorithm

In order to clip polygon edges against a window edge we move from vertex Vi to the subsequent vertexVi+1 and choose the output vertex as per to four simple tests or rules or cases listed here in below:

Table: Cases of the Sutherland-Hodgman Polygon Clipping Algorithm

Case

Vi

Vi+1

Output Vertex

A

Inside window)

Inside

Vi+1

B

Inside

Outside

V'i   i.e  intersection of polygon and window edge

C

Outside

Outside

None

D

Outside

Inside

V'I  ; Vi+1

Conversely, the 4 possible Tests listed above to clip any polygon conditions are as mentioned here:

1) If both Input vertices are within the window boundary then only second vertex is added to output vertex list.

2) If first vertex is within the window boundary and the 2nd vertex is outside then, merely the intersection edge along with boundary is added to output vertex.

3) If both Input vertices are outside the window boundary then nothing is added to the output list.

4) If the first vertex is outside the window and the 2nd vertex is within window, then both the intersection points of the polygon edge along with window boundary and second vertex are added to output vertex list.

Here, we can utilize the rules cited above to clip a polygon properly. The polygon should be tested against each edge of the clip rectangle; new edges should be added and existing edges must be discarded, retained or divided. In fact this algorithm decomposes the problem of polygon clipping against a clip window in the same sub-problem where a sub-problem is to clip all polygon edges that is pair of vertices in succession against a particular infinite clip edge. The output is a set of clipped edges or pair of vertices which fall in the visible side along w.r.t. clip edge. Such set of clipped edges or output vertices are taken as input for the subsequent sub-problem of clip against the second window edge. Hence, identifying the output of the earlier sub-problem as the input, all of the sub-problems are solved in sequence, at last yielding the vertices which fall on or inside the window boundary. These vertices linked in order forms, the shape of the clipped polygon.


Related Discussions:- Cases of the sutherland hodgman polygon clipping algorithm

Behavioral animation - computer animation, Behavioral Animation - Computer ...

Behavioral Animation - Computer Animation It used for control the motion of several objects automatically. Objects or "actors" are specified rules about how they respond to th

Computer animation tools, Computer Animation Tools  To create various t...

Computer Animation Tools  To create various types of animation discussed above, we want to have particular software and hardware as well. Here, the fundamental constraint is re

Types of graphic images, Types of Graphic Images: Graphic images have...

Types of Graphic Images: Graphic images have been processed through a computer can generally be divided in two distinct categories. That image is either bitmap files or vecto

Frame, what is frame buffer

what is frame buffer

Intensity of colours - raster graphics and clipping, Similarly we can contr...

Similarly we can control the intensity of colours We contain more bit planes for all colour say three bit planes for R, 3 for G and 3 for B here all bit plane of size mxn, hen

Tones and tints, Q. What is the difference between tones and tints? Which o...

Q. What is the difference between tones and tints? Which one component of YIQ color model does black- and- white television use? How can you convert a ZTSC video signal to an RGB s

Odd-even rule and non-zero winding number rule, What is the difference betw...

What is the difference between odd-even rule and non-zero winding number rule to identify interior regions of an object? Develop an algorithm for a recursive method for filling a 4

Surface of revolution - modeling and rendering, Surface of Revolution - Mod...

Surface of Revolution - Modeling and Rendering In the previsions sections we have learned different type of techniques of generating curves, although if we wish to generate a

Sutherland hodgeman polygon clipping algorithm, What is clipping? Explain S...

What is clipping? Explain Sutherland Hodgeman polygon clipping algorithm with example.  OR Write the algorithm for Sutherland Hodgeman Polygon. Beginning with the initial set of p

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