UnityShader学习9 动态变色

 

Shader "ShaderLearn/my_test_03" {
    Properties {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0

        _MainColor("MainColor", color) = (1,1,1,1)
        _SecondColor("SecondColor", color) = (1,1,1,1)
        _Center("Center", range(-0.51, 0.51)) = 0
        _R("R", range(0, 1)) = 0
    }
    SubShader {
        Tags { "RenderType"="Opaque" }
        LOD 200
        
        CGPROGRAM
        
        #pragma surface surf Standard fullforwardshadows vertex:vert

        #pragma target 3.0


        sampler2D _MainTex;
        fixed4 _MainColor;
        fixed4 _SecondColor;
        float _Center;
        float _R;

        struct Input {
            float2 uv_MainTex;
            float x;
        };

        half _Glossiness;
        half _Metallic;
        fixed4 _Color;

        
        UNITY_INSTANCING_CBUFFER_START(Props)
        UNITY_INSTANCING_CBUFFER_END
        
        void vert(inout appdata_full v, out Input o)
        {
            o.uv_MainTex = v.texcoord.xy;
            o.x = v.vertex.x;
        }

        void surf (Input IN, inout SurfaceOutputStandard o) {
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = c.rgb;
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = c.a;

            float d = IN.x - _Center;
            float s = abs(d);//正
            d = d / s;//1或者-1

            float f = s / _R;
            f = saturate(f);
            d *= f;

            d = d / 2 + 0.5;//变成0到1


            o.Albedo *= lerp(_MainColor, _SecondColor, d);
        }
        ENDCG
    }
    FallBack "Diffuse"
}