shader之调整屏幕的亮度、饱和度和对比度
1.对于屏幕处理效果都要继承自PostEffectsBase，新建一份c#脚本BrightnessSaturationAndContrast（需挂在摄像机上）
public class BrightnessSaturationAndContrast : PostEffectsBase {
public Shader briSatConShader;
private Material briSatConMaterial;
public Material material {
get {
briSatConMaterial = CheckShaderAndCreateMaterial(briSatConShader, briSatConMaterial);
return briSatConMaterial;
}
}
[Range(0.0f, 3.0f)]
public float brightness = 1.0f;
[Range(0.0f, 3.0f)]
public float saturation = 1.0f;
[Range(0.0f, 3.0f)]
public float contrast = 1.0f;
void OnRenderImage(RenderTexture src, RenderTexture dest) {
if (material != null) {
material.SetFloat("_Brightness", brightness);
material.SetFloat("_Saturation", saturation);
material.SetFloat("_Contrast", contrast);
Graphics.Blit(src, dest, material);
} else {
Graphics.Blit(src, dest);
}
}
}
2.新建一份顶点着色器的shader代码
Shader "Unity Shaders Book/Chapter 12/Brightness Saturation And Contrast" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
_Brightness ("Brightness", Float) = 1
_Saturation("Saturation", Float) = 1
_Contrast("Contrast", Float) = 1
}
SubShader {
Pass {
ZTest Always Cull Off ZWrite Off
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
sampler2D _MainTex;
half _Brightness;
half _Saturation;
half _Contrast;
struct v2f {
float4 pos : SV_POSITION;
half2 uv: TEXCOORD0;
};
v2f vert(appdata_img v) {
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.texcoord;
return o;
}
fixed4 frag(v2f i) : SV_Target {
fixed4 renderTex = tex2D(_MainTex, i.uv);
fixed3 finalColor = renderTex.rgb * _Brightness;
fixed luminance = 0.2125 * renderTex.r + 0.7154 * renderTex.g + 0.0721 * renderTex.b;
fixed3 luminanceColor = fixed3(luminance, luminance, luminance);
finalColor = lerp(luminanceColor, finalColor, _Saturation);
fixed3 avgColor = fixed3(0.5, 0.5, 0.5);
finalColor = lerp(avgColor, finalColor, _Contrast);
return fixed4(finalColor, renderTex.a);
}
ENDCG
}
}
Fallback Off
}
注：该shader要拖动到摄像机脚本BrightnessSaturationAndContrast的briSatConShader变量中运行
实现效果：
