Steps for clip a line segment-pq, Computer Graphics

Steps for clip a line segment-PQ

  • Initially, find all the points of intersections of the line segment PQ along with the edges of the polygonal window and describe them either as PE and PL points. Also find out the value of parameter t, by using equation (2) for respective PE's and PL's.

                                                            Or

If value of the normal to particular edges is not specified then, determine the value of normal to every edge of the window, then find out the value of parameter t, by using equation (2) for particular point of intersection among line segment and window edge then on the basis of the value of parameter t mark them like PE and PL given the value of t lies from 0 to 1 in magnitude.

  • Secondly, out of the diverse values of t for PE's find out the maximum value of t say it is tmax. Likewise, out of the diverse values of t for PL's find out the minimum value of t say it be tmin . Remember here that for clipping to be possible tmin > tmax.
  • at last, vary the parameter t from tmax to tmin and find out the clipped line as outcome.

For well understanding of steps here figure is shown below:

2071_Steps for clip a line segment-PQ.png

Figure: Steps of Cyrus Beck Clipping

During in case of Line 1: (PQ)

1) Point 1 is potentially entering (PE1) since as we move along PQ, the LHS of e1 is window and hence, it seems that we are entering the window.

2) Point 2 is again PE2 same as point 1.

3) Point 3 is potentially leaving (P4) ? as we move along PQ, the LHS of e2 is window and hence, it seems that we are leaving the window.

4) As the same, point 4 is also PL2.

Line 2 and 3 (PQ):

By using similar logic as for line 1 we determine p‾L and PE. Here, it is to be noted that for all points of intersection we have several value of t.

Say t1 is value of t for PE1

Say t2 is value of t for PE2

Say t3 is value of t for PL1

Say t4 is value of t for PL2

Posted Date: 4/3/2013 3:30:04 AM | Location : United States







Related Discussions:- Steps for clip a line segment-pq, Assignment Help, Ask Question on Steps for clip a line segment-pq, Get Answer, Expert's Help, Steps for clip a line segment-pq Discussions

Write discussion on Steps for clip a line segment-pq
Your posts are moderated
Related Questions

Variation of Intensity - Modeling and Rendering According to the phong model the variation of Intensity (I) along with α (since I α cos n α) is: i) for shiny surface (

Define the term -Monitoring Chemical and nuclear plants (monitoring key parameters), hospitals (monitoring patient's vital signs), burglar alarms (monitoring for intruders) etc

What is translation?  Translation is the process of changing the position of an object in a straight-line path from one coordinate location to another. Each point (x, y) in the

What are the advantages of Bresenham's line drawing algorithm over DDA line drawing algorithm? DDA and Bresenham algorithms both are efficient line drawing algorithm. Breaenham

Applications that can handle Vector Data There are hundreds of applications under the market which can be used to modify or make vector data. In prepress: Adobe Illustrator, Ma

To reflect the ball off of the polyline, we need to re?ect it off of the segment that had the minimum thit. But the reflection computation depends only on t hit , n, P and v, so th



QUESTION (a) Give some ways you can change the magnification of a document? (b) Give three ways to display a panel? (c) Identify the differences between Selection tool an