Unity Shader - Sprite Shader之简单抠图

在PhotoShop中我们经常会用到抠图操作，现在就用Shader实现一个简单的抠图效果。使用当前像素颜色与需要抠掉的颜色相减作比较，然后与一个指定的阈值比较以决定是否将其显示出来；

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2018-05-30 13:54  Demo-SpriteShader\
     目录           0  2018-05-30 15:01  Demo-SpriteShader\Demo\
     目录           0  2018-05-30 15:01  Demo-SpriteShader\Demo\Assets\
     文件       15176  2018-05-30 15:01  Demo-SpriteShader\Demo\Assets\Demo.unity
     文件         174  2018-05-30 14:34  Demo-SpriteShader\Demo\Assets\Demo.unity.meta
     目录           0  2018-05-30 14:48  Demo-SpriteShader\Demo\Assets\Materials\
     文件        4928  2018-05-30 14:48  Demo-SpriteShader\Demo\Assets\Materials\lotus1.mat
     文件         179  2018-05-30 14:32  Demo-SpriteShader\Demo\Assets\Materials\lotus1.mat.meta
     文件        4928  2018-05-30 14:48  Demo-SpriteShader\Demo\Assets\Materials\lotus2.mat
     文件         179  2018-05-30 14:40  Demo-SpriteShader\Demo\Assets\Materials\lotus2.mat.meta
     文件         191  2018-05-30 13:59  Demo-SpriteShader\Demo\Assets\Materials.meta
     目录           0  2018-05-30 14:58  Demo-SpriteShader\Demo\Assets\Shaders\
     文件        2751  2018-05-30 14:58  Demo-SpriteShader\Demo\Assets\Shaders\SpriteShader.shader
     文件         195  2018-05-30 13:55  Demo-SpriteShader\Demo\Assets\Shaders\SpriteShader.shader.meta
     文件         191  2018-05-30 13:55  Demo-SpriteShader\Demo\Assets\Shaders.meta
     目录           0  2018-05-30 14:10  Demo-SpriteShader\Demo\Assets\Textures\
     文件      201886  2018-05-30 14:07  Demo-SpriteShader\Demo\Assets\Textures\lotus1.png
     文件        1205  2018-05-30 14:10  Demo-SpriteShader\Demo\Assets\Textures\lotus1.png.meta
     文件      283353  2018-05-30 14:07  Demo-SpriteShader\Demo\Assets\Textures\lotus2.png
     文件        1205  2018-05-30 14:10  Demo-SpriteShader\Demo\Assets\Textures\lotus2.png.meta
     文件         191  2018-05-30 13:55  Demo-SpriteShader\Demo\Assets\Textures.meta
     文件         549  2018-05-30 13:55  Demo-SpriteShader\Demo\Demo.sln
     文件         497  2018-05-30 15:01  Demo-SpriteShader\Demo\Demo.userprefs
     目录           0  2018-05-30 15:01  Demo-SpriteShader\Demo\Library\
     文件        5120  2018-05-30 14:48  Demo-SpriteShader\Demo\Library\AnnotationManager
     文件           8  2018-05-30 13:54  Demo-SpriteShader\Demo\Library\AssetImportState
     文件        4756  2018-05-30 15:01  Demo-SpriteShader\Demo\Library\AssetServerCacheV3
     文件       14336  2018-05-30 14:32  Demo-SpriteShader\Demo\Library\AssetVersioning.db
     文件           0  2018-05-30 13:54  Demo-SpriteShader\Demo\Library\BuildPlayer.prefs
     文件        4128  2018-05-30 13:54  Demo-SpriteShader\Demo\Library\BuildSettings.asset
     文件       35568  2018-05-30 15:01  Demo-SpriteShader\Demo\Library\CurrentLayout.dwlt
............此处省略398个文件信息