volumetric lighting on a single light. - Lighting and Rendering - Blender Artists Community
How to fake volumetric light cones - 60 second tutorial 3 - BlenderNation
eMirage - quick tip : Volumetric light rays with Blender Cycles. 1-create a box adjust its shape and assign to it a new material 2-create a sun lamp, change the sun's color
rendering - Atmospheric lighting in cycles - Blender Stack Exchange