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What is line clipping and polygon clipping?
Note the difference between this strategy for a polygon and the Cohen-Sutherland algorithm for clipping a line: The polygon clipper clips against four edges in succession, whereas the line clipper tests the outcode to see which edge is crossed, and clips only when necessary.
What is the polygon clipping?
Polygon clipping is an important operation that computers,execute all the time. An algorithm that clips a polygon is rather complex. Each edge ofthe polygon must be tested against each edge of the clipping window, usually a rectangle. Multiple polygons may result from clipping a single polygon.
How many edges of the polygon clipping are is present in 2D?
How many edges of the clipping are/is present in 2D? Explanation: If the algorithm is done in 2D, we have 4 edges of the clipping area. Left edge, right edge, top edge and bottom edge.
What is line-clipping algorithm?
In computer graphics, line clipping is the process of removing lines or portions of lines outside an area of interest. There are two common algorithms for line clipping: Cohen–Sutherland and Liang–Barsky. A line-clipping method consists of various parts.
Why is polygon clipping difficult?
Polygon clipping is particularly difficult because it is necessary that closed polygons remain closed. Clipping a polygon can result in several disjoint polygons. Typical algorithms include the Sutherland–Hodgman and the Weiler–Atherton clipping algorithms.
Which is the correct way to clip polygons?
Case2) Right clip: In the right-side polygon clipping, we only remove the right part of the polygon, which is outside the window. We only save the portion which is inside the window. Case3) Top clip: On the top side polygon clipping, we only remove the top part of the polygon, which is outside the window.
What does condition 4 in polygon clipping mean?
Condition 4 (Out-Out): If both vertices of the polygon are outside the window, then the output will be nothing. It means we found a clipped polygon. This algorithm helps us to clip a filled area. The filled area may be a convex polygon or concave polygon. This algorithm was introduced to identify the visible surfaces.
What is Step 3 of line clipping algorithm?
Step 3.1 : If the result is not 0000, then given line is completely outside. Step 3.2 : Else line is partially inside. Step 3.2.1 : Choose an endpoint of the line that is outside the given rectangle. Step 3.2.2 : Find the intersection point of the rectangular boundary (based on region code).
How to clip a line outside a rectangle?
Step 3.2 : Else line is partially inside. Step 3.2.1 : Choose an endpoint of the line that is outside the given rectangle. Step 3.2.2 : Find the intersection point of the rectangular boundary (based on region code). Step 3.2.3 : Replace endpoint with the intersection point and update the region code.