Unity3D图像后处理特效——Toonmapping
Tonemapping is usually understood as the process of mapping color values fromHDR (high dynamic range) to LDR (low dynamic range). In Unity, this means for most platforms that arbitrary 16-bit floating point color values will be mapped to traditional 8-bit values in the [0,1] range.
Tonemapping 通常被理解为将颜色值从高动态范围（HDR）映射到低动态范围（LDR）的过程。在Unity中，这意味着对于大多数平台上任意16位的浮点型颜色值将被映射为 [0，1]范围内的传统8位颜色值。
Tonemapping will only properly work if the used camera hasHDR enabled. It is also recommended to give light sources higher than normal intensity values to make use of the bigger range. Additionally, the Bloom image effect supports HDR and can help giving your lights higher ranges and is typically used in conjunction with Tonemapping.
Tonemapping只有在相机启用HDR时才能正常工作。建议给光源高于正常强度的亮度，从而让其具有更大的范围。此外，辉光（Bloom）图像特效支持 HDR，并且可以帮助让您的灯光拥有更高的范围，通常与 Tonemapping一起使用。
There is many different ways on how to map intensities to LDR (as selected byMode). This effect provides several techniques, two of them being adaptive (AdaptiveReinhard andAdaptiveReinhardAutoWhite), which means that color changes are carried out delayed as the change in intensities is fully registered. Cameras and the human eye have this effect. This enables interesting dynamic effects such as a simulation of the natural adaption happening when entering or leaving a dark tunnel into bright sunlight.
对于如何将亮度映射到低动态范围有许多种不同的方法，这种特效提供多种技术，其中两个是自适应的（AdaptiveReinhard 和AdaptiveReinhardAutoWhite），这意味着颜色的变化可以滞后于亮度的变化。相机和人眼都具有这种效应。这样可以实现一些有趣的动态特效，比如模拟突然间从明亮的阳光下进入或离开阴暗桥洞的颜色自然调整过程。
As with the otherimage effects, this effect is only available in Unity Pro and you must have the Pro Standard Assets installed before it becomes available.
和其他图像特效一样，该特效只能在Unity Pro上进行使用，并且在使用之前必须安装Pro Standard Assets。
Properties 属性
| Mode 模式 | Choose the desired tonemapping algorithm. 选择想要的颜色映射算法 |
| Exposure 曝光度 | Simulated exposure, defining the actual range of luminances. 模拟曝光度，定义真实的亮度范围 |
| Average grey 平均灰度 | Average grey value of the scene that defines the intensity of the result. 平均场景中亮度的灰度值 |
| White 白色 | Smallest value that will be mapped white. 最小的值将被映射为白色 |
| Adaption speed 调整速度 | Adjustment speed for all adaptive tonemappers. 对于所有自适应色调映射器的调整速度 |
| Texture size 纹理大小 | Size of the internal texture for all adaptive tonemappers. Bigger values capture more details when calculating the new intensity and lower performance. 所有自适应色调映射器的内部纹理，比较大的值可以在计算新亮度时获得更多的细节，但具有较低的性能 |
Hardware support 硬件支持
This effect requires a graphics card with pixel shaders (2.0) or OpenGL ES 2.0. PC: NVIDIA cards since 2003 (GeForce FX), AMD cards since 2004 (Radeon 9500), Intel cards since 2005 (GMA 900); Mobile: OpenGL ES 2.0; Consoles: Xbox 360, PS3.
这个特效需要显卡拥有像素着色器（2.0）或者OpenGL ES 2.0。台式机：2003年以后的NVIDIA显卡（GeForce FX），2004年以后的AMD显卡（Radeon 9500），2005年以后的Intel卡（GMA 900）；移动设备：OpenGL ES 2.0；控制台： Xbox 360、 PS3。
All image effects automatically disable themselves when they can not run on end-users graphics card.
所有图像特效如果无法在用户显卡上运行时将会自动被关闭。