# 数学（Math）节点

Epsilon

## 属性

Raises Euler's number to the power of the value.

Returns the fractional part of the value.

## 示例

### 自定义Z深度通道节点设置

"使用最小值" 功能是依据靠近摄影机的像素将Z深度值选择出来；也可以选择矩形部分的平面Z深度值。背景有个初始的Z深度值，值限定为1.0（显示为白色）。在 "使用最大值" 范例中，矩形的Z深度值比图像平面要大，因此更靠近左侧，但是图像平面（FlyCam）渲染层Z值初始在右侧（对应于1.0），因此他们被选择。

### 提亮（缩放）通道

This example has a Math (Multiply) node increasing the luminance channel (Y) of the image to make it brighter. Note that you should use a Map Value node with min() and max() enabled to clamp the output to valid values. With this approach, you could use a logarithmic function to make a high dynamic range image. For this particular example, there is also a Brightness/Contrast node that might give simpler control over brightness.

### 重新限定颜色选择（色调分离）

To split up a continuous range of values between 0 and 1 to certain set of values, the following function is used: $$round(x × n - 0.5) / (n - 1)$$, where "n" is the number of possible output values, and "x" is the input pixel color. Read more about this function.