9.5.2

328 • CHAPTER 7
OBJECTS MENU • LIGHTING • 329
None
Select None if your light is to cast no shadow. This is a very helpful option in a scene with many lights,
allowing you to turn on shadow-casting for the main lights only. Any real world photographer will
envy you this option and its possibilities.
Shadow Maps (soft)
In reality all objects — whether they are trees growing in the wild, or a vase in a room — are lit by
several partial light sources. The result of this is a gradual transition of light to shadow. This soft edge,
or umbra, can be simulated in CINEMA 4D by using a ‘shadow map’. A shadow map is a grayscale
picture of the scene as viewed from the light source. Contained in this are all the objects lit by the
light source.
During the render calculation the renderer will determine exactly which objects will fall into this
shadow of the light source. The major advantage of this method is the high computing speed and the
soft shadow’s natural appearance. However, the one downside to soft shadows is the memory needed.
Depending on the size of the shadow map, a great deal of additional memory may be needed. So be
careful in your allocation of shadow maps or you may nd your scenes wasting precious memory.
Raytraced (hard)
Traditionally in raytracers, genuinely raytraced scenes contained hard shadows. As this technique
needed to compute many more additional rays, this method increases the render time dramatically.
Hard shadows, because of their abrupt, sharp appearance, are of particular interest for technical
illustrations. However, in other more natural pictures they look rather unrealistic because such hard,
sharp shadow borders are rarely found in real world environments.
Area
Although Soft shadows are more natural than Hard shadows, they are still not perfectly natural. On
careful examination you can see that the soft edge always has the same width. In nature this does
not happen; the closer an object is to a surface on which it casts its shadows, the sharper this edge
will be. Area shadows simulate this effect.
CINEMA 4D calculates the shadow at the origin of the light source outwards (for all lights, whether
Omni, Spot or Area). Only a hard shadow is computed at this point. The softer Area shadow is the
result of a virtual Area light source that simulates the overlay of several light sources. This provides the
natural scattering of light. However, as usual, this method comes with a price: it adds to the render
time. Carefully assigned Area shadows, however, can produce very realistic shadows.