Lens Blur

Imitates a camera capturing the image out of focus by using a blur that generates the large shapes known as bokeh. The polygonal shape of real bokeh is due to the blades of the aperture diaphragm when it isn't fully open. This blur renders bokeh from a 6-bladed diaphragm because the computation is more efficient. It can be separated into three rhombi, each of which is just a skewed box blur.