Scanline rendering

Scanline algorithm is a rendering algorithm in 3D computer graphics that works on a point-by-point basis rather than polygon-by-polygon basis. You calculate some point in a line and then move to the next point in the line. When the line is finished, you move to the next one.

The asset of this method is that you don't have translate coordinates of all vertexes from the main memory into the working memory area each time you encounter new polygon, but it's very probable that you have some of the vertexes already loaded in memory from neighbor polygons. Memory bus is often very slow compared to the central processing unit and working memory (often cache memory) and thus it can provide substantial speed-up.

This kind of algorithms can be easily integrated with the [[Phong reflection model]] and Z-buffer algorithm.