Chromatic Aberration 色差
本文檔主要是對Unity官方手冊的個人理解與總結（其實以翻譯記錄爲主：>）
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文章中涉及到的操作都是基於Unity2018.4版本
參考鏈接：https://github.com/Unity-Technologies/PostProcessing/wiki/Chromatic-Aberration
In photography, chromatic aberration is an effect resulting from a camera’s lens failing to converge all colors to the same point. It appears as “fringes” of color along boundaries that separate dark and bright parts of the image.
在攝影中，色差是由於照相機的鏡頭不能將所有的顏色匯聚到同一點而產生的一種效應。它以顏色的“條紋”的形式把圖像分隔出暗部和亮部的邊界。
The Chromatic Aberration effect is used to replicate this camera defect, it is also often used to artistic effect such as part of camera impact or intoxication effects. This implementation provides support for red/blue and green/purple fringing as well as user defined color fringing via an input texture.
色差效應是用來重現這一相機缺陷的，它也經常用於藝術效果，如部分相機的撞擊或陶醉效果。該實現支持紅/藍、綠/紫邊以及用戶通過輸入紋理定義的顏色條。
Properties
| Property | Function |
|---|---|
| Spectral Lut | Texture used for custom fringing color (will use default when empty). |
| 光譜查找表 | 用於自定義顏色條紋理(將使用默認時爲空)。 |
| Intensity | Strength of chromatic aberrations. |
| 強度 | 色差強度 |
| Fast Mode | Use a faster variant of the effect for improved performances. |
| 快速 | 使用一個更快的變體的效果，以提高性能。 |
Details
Chromatic Aberration uses a Spectral Lut input for custom fringing. Four example spectral textures are provided in the repository:
色差使用光譜查找表（可自定義顏色條）。庫中提供了四個光譜紋理示例:
- Red/Blue (Default)
- Blue/Red
- Green/Purple
- Purple/Green
You can create custom spectral textures in any image editing software. Their resolution is not constrained but it is recommended that they are as small as possible (such as the 3x1 textures provided).
您可以在任何圖像編輯軟件中創建自定義的光譜紋理。它們的分辨率不受限制，但建議儘可能小(如提供的3x1紋理)。
You can achieve a less smooth effect by manually setting the Filter Mode of the input texture to Point (no filter).
您可以通過手動將輸入紋理的過濾模式設置爲Point(no filter)來獲得不太平滑的效果。
Performances
Performances depend on the Intensity value (the higher it is, the slower the render will be as it will need more samples to render smooth chromatic aberrations).
性能取決於強度值(它越高，渲染就會越慢，因爲它需要更多的樣本來渲染平滑的色差)。
Enabling Fast Mode is also recommended whenever possible as it’s a lot faster, albeit not as smooth as the regular mode.
如果可能，也建議啓用快速模式，因爲它要快得多，儘管不如常規模式平滑。
Requirements
- Shader Model 3
See the Graphics Hardware Capabilities and Emulation page for further details and a list of compliant hardware.