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16.4.1 Using Backface/Frontface Removal

To reduce fill-limited drawing, use backface and frontface removal. For example, if you are drawing a sphere, half of its polygons are backfacing at any given time. Backface and frontface removal is done after transformation calculations but before per-fragment operations. This means that backface removal may make transform-limited polygons somewhat slower, but make fill-limited polygons significantly faster. You can turn on backface removal when you are drawing an object with many backfacing polygons, then turn it off again when drawing is completed.