使用纹理制作特效 - Photoshop色阶效果

最新推荐文章于 2025-11-14 17:57:15 发布

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本文介绍了一种使用Unity Shader来模拟Photoshop级别调整效果的方法。通过定义输入和输出黑白点、伽玛值等参数，该Shader可以在实时渲染中调整纹理的亮度和对比度。这种技术适用于希望在游戏中实现高质量图像后期处理效果的开发者。

Shader "PhotoshopLevels"
{
    Properties
    {
        _MainTex("MainTex", 2D) = "" {}

        _InBlack("InBlack", Range(0, 255)) = 0
        _InGamma("InGamma", Range(0, 255)) = 1.61
        _InWhite("InWhite", Range(0, 255)) = 255
        _OutBalck("OutBlack", Range(0, 255)) = 0
        _OutWhite("OutWhite", Range(0, 255)) = 255
    }

    SubShader
    {
        Tags
        {
            "RenderType" = "Opaque"
        }

        LOD 200

        CGPROGRAM

        #pragma surface surf Lambert

        sampler2D _MainTex;

        float _InBlack;
        float _InGamma;
        float _InWhite;
        float _OutBlack;
        float _OutWhite;

        float outRPixel;

        struct Input
        {
            float2 uv_MainTex;
        };

        void surf(Input IN, inout SurfaceOutput o)
        {
            float4 c = tex2D(_MainTex, IN.uv_MainTex);

            outRPixel = c.r * 255.0;

            outRPixel = max(0, outRPixel - _InBlack);

            outRPixel = saturate(pow(outRPixel / (_InWhite - _InBlack), _InGamma));

            outRPixel = (outRPixel * (_OutWhite - _OutBlack) + _OutBlack) / 255.0;

            c.r = outRPixel;

            o.Albedo = c.rgb;
            o.Alpha = c.a;
        }

        ENDCG
    }
}