OpenGL Distilled

A.6. The Accumulation Buffer

The accumulation buffer is a part of the framebuffer that can't be rendered to directly. Applications can add rendered images from the color buffer into the accumulation buffer, however. By combining several images, applications use the accumulation buffer to create several effectsnotably motion blur, soft shadows, and depth of field. Although accumulation-buffer operations can be accelerated in hardware (Haeberli 1990), the accumulation buffer has a reputation for poor performance. The accumulation buffer has been in OpenGL since version 1.0.

For a complete overview of the accumulation buffer, see Chapter 10, "The Framebuffer," of OpenGL^® Programming Guide and "glAccum" in OpenGL^® Reference Manual.