Drop shadows Or Cast shadows(译文)

1. A drop shadow duplicates the shape and size of an object or text and makes it appear that object or text is floating in front of the background. The drop shadow is placed behind the object and offset slightly depending on the position of the imaginary light source and the imaginary distance of the object from the background.

阴影是复制目标对象的形状和大小，使得这个对象浮在背景表面。阴影被置于对象的后边取决于虚构的光源的位置与对象远离背景的距离。

2. A cast shadow, also called a perspective shadow, adds a more realistic element of perspective. Instead of floating above or in front of a surface, the cast shadow anchors an object to one surface while giving the illusion of being in front of another surface. Cast shadows look more like the shadow cast by a person or a tree or a building. Instead of floating detached behind the object it extends from the object out across one or more surfaces in front of, behind , or to the side. Through rotation, stretching, and skewing the cast shadow mimics the shadows cast by the sun or other lights. A light almost directly above an object may cause a short, flat shadow. A light closer to the horizon may cause a long, narrow shadow.

投影也被称作透视阴影，一个更真实的视角。它与悬浮在背景面上不同，把对象投射到一个平面，同时形成一种在另一个面的假象。一个人或者一棵树或者一栋建筑的投影看起来更真实。与浮在对象后边不同，投影往往是出现在一个或者多个面，在对象的前边，后边或者旁边。通过旋转，拉伸，位移等来模仿真实太阳等光源下的投影效果。从上投射下来的光可能出现比较短而宽的投影；而从比较靠近水平线的位置投射的可能出现长而窄的投影。

3. Other shadow effects: Through graphics software the designer can do other special effects similar to drop shadows and cast shadows. A glow effect is like a soft shadow all ground an object. Wind or motion blur creates shadows that make it appear the object is moving. 3D or embossing filters place shadows around the edges that give a raised lettering effect. Another aspect of cast shadows are from shadows. When a shadow is cast it means that one side of the objects is facing the light source. The side of the object away from the light source will be dark, softer, in shadow. Depending on the strength of the light, this from shadow may not be quite pronounced.

其他形式的阴影效果。设计师通过一些设计软件可以做出其他的特殊效果来模仿阴影和投影。光晕就像一种软阴影包裹在对象四周。运动模糊模拟一种对象在移动的现象。而3D或者浮雕滤镜使得对象的边缘有阴影形成一种凸起的效果。投影的另一点就是形成影子。出现投影意味着对象的另一边是对着光源的，背离光源的那一面是暗的，模糊的。这取决于光照强度，这种形式的阴影可能并不那么明显。