在真实世界中，光线的强度会随距离的增大而递减。这是因为受到了空气中微粒的衍射影响，而在3D Studio MAX中，场景处于理想的“真空”中，理论上无这种现象出现。但这种现象与现实世界不符，因此为了达到模拟真实的效果，在灯光中加入该选项，就能人为的产生这种效果！
In physics, attenuation (in some contexts also called extinction) is the gradual loss in intensity of any kind of flux through a medium. For instance, sunlight is attenuated by dark glasses, and X-rays are attenuated by lead.
In electrical engineering and telecommunications, attenuation affects the propagation of waves and signals in electrical circuits, in optical fibers, as well as in air (radio waves).
在物理上。attenuation（衰减）指的是某种流体通过某种物体时密度上的损失。例如。阳光通过黑色镜子时的衰减。X射线通过铅的时候。
在电子工程、计算机网络、通讯方面，衰减影响光波和信号的繁殖。