Algorithm for scan line method

Question

Write down the algorithm for scan line method?

Answer 1

Algorithms for scan line method are as follows:

For each scan line execute step 1 via step 3.

1) For all pixels on a scan line, set depth[x] = 1.0(max value) & intensity[x] = background color.

2) For each polygon in the scene, find all pixels on the present scan line (say s1) that lies in the polygon. For each of these x-values:

i). compute the depth z of the polygon at (x,y)

ii). When z < depth[x], set depth[x] = z and intensity corresponding to the polygons shading

3) Subsequent to all the polygons have been taken into consider; the values enclosed in the intensity array symbolize the solution and can be copied into a frame buffer.

The advantage of scan line algorithm is that every time, we are functioning with one dimensional array that is, x[0….x-max] for color not a 2-D array as in depth buffer algorithm.