AreaLight

From Odwiki

Most lights in CG are infinitely small point lights. Area lights are lights which have actual dimensions (think of a neon tube, or the sun) and so the we can get a lot closer to actual lighting phenomena. Shadows blur correctly when we use area lights. mantra supports area lights for various preset primitive shapes; line, rectangle, box, circle, sphere and tube.

Area lights are computed by sampling often within the light shape. This "Number Of Samples" control on the light is the basic quality-versus-speed knob.

You can find these settings in the LightObject's ParameterPane.

[edit] Notes

• Area lights can only shadow "correctly" using RayTraced shadows. They may still use ZDepthMaps?, but the shadowing will be as inaccurate as with point lights.
• Area lights do not affect LightAttentuation.