Image space methods Flashcards
What is so different in scan line, A or Z buffer
It has depth for only single scan line
True/ False
we must group and process all
polygons intersecting a given scan-line at the same time before process the
next scan-line
true
What kind of table is maintained in the scan line?
Active edge table
How does an AET work?
Maintain active-edge-table as we
visit each scan-line in scene. AET now contains edges for all polygons at that
scanline. Must maintain flag for each surface to determine whether pixel on
scan-line is inside that surface
When does scan line method generalization fail?
+Provide a remedy
This basic approach fails when surfaces cut-through each other or overlap. To
generalize we must divide surfaces to eliminateoverlaps
in what direction is scan line moving
left to right
in case of working of scanline where is the refresh buffer entered?
the intensity of the nearest position
What tables are maintained for the surfaces?
Edge table : for coordinates,inverse slope,pointers,identify the surfaces bounded by each line
Polygon table:
Coefficients of the plane of each surface
Intensity information
Pointers in the edge table
what is the entity contained in the edge across the current scan line.
Active list
what indicates whether or not the scan line is inside or outside the surface?
hint: I had al the red _____ that he was the best man ever
Flag
Define Area Subdivision method?
Recursively subdivide view plane into quadrants until:
– rectangle contains part of 1 projected surface
– rectangle contains part of no surface
– rectangle is size of pixel
does the recursive subdivision stop if the rectangle has all the surfaces inside, two or more overlapping surfaces, and the rectangle does not have any surface
False
compare the rectangle to what for efficiency
projected surface bounding
can we casually perform the exact interaction test if necessary,
no
on what exactly is the test performed
for exact intersection and color the frame buffer for the intersection of the surface and rectangle
