29-06-2012, 01:09 PM
Scan conversion
[attachment=26087]
The scan conversion is digitation of picture definition into set of pixel intensity value for storage in frame buffer .
E.g :- line drawing is accomplished by calculating intermediate positions along the line path between two specific endpoint positions.
Considerations
Considerations to keep in mind:
The line has to look good
Avoid jaggies
It has to be lightening fast!
How many lines need to be drawn in a typical scene?
This is going to come back to bite us again and again
A Very Simple Solution
We could simply work out the corresponding y coordinate for each unit x coordinate
Let’s consider the following example:
A Quick Note About Slopes
If the slope of a line is between -1 and 1 then we work out the y coordinates for a line based on it’s unit x coordinates
Otherwise we do the opposite – x coordinates are computed based on unit y coordinates
[attachment=26087]
The scan conversion is digitation of picture definition into set of pixel intensity value for storage in frame buffer .
E.g :- line drawing is accomplished by calculating intermediate positions along the line path between two specific endpoint positions.
Considerations
Considerations to keep in mind:
The line has to look good
Avoid jaggies
It has to be lightening fast!
How many lines need to be drawn in a typical scene?
This is going to come back to bite us again and again
A Very Simple Solution
We could simply work out the corresponding y coordinate for each unit x coordinate
Let’s consider the following example:
A Quick Note About Slopes
If the slope of a line is between -1 and 1 then we work out the y coordinates for a line based on it’s unit x coordinates
Otherwise we do the opposite – x coordinates are computed based on unit y coordinates