[游戏开发]让进度条颜色渐变的shader

2.先写shader代码

Shader "Unlit/TheGradientShader"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _TexTintColor("Texture Tint Color", Color) = (1,1,1,1)
        _PlaneColor("Plane Color", Color) = (1,1,1,1)
        _Unity("_Unity", float) = 1.5
    }
    SubShader
    {
        Tags { "RenderType"="Transparent" "Queue"="Transparent" }
        LOD 100
        Blend SrcAlpha OneMinusSrcAlpha
        ZWrite Off
 
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            
            #include "UnityCG.cginc"
 
            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                float3 uv2 : TEXCOORD1;
            };
 
            struct v2f
            {
                float4 vertex : SV_POSITION;
                float2 uv : TEXCOORD0;
                float3 uv2 : TEXCOORD1;
            };
 
            sampler2D _MainTex;
            float4 _MainTex_ST;
            fixed4 _TexTintColor;
            fixed4 _PlaneColor;
            float _ShortestUVMapping;
            float _Unity;
          
 
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                o.uv2 = v.uv2;
                return o;
            }
            
            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col = tex2D(_MainTex, i.uv) * _TexTintColor;
                col = lerp( _PlaneColor, col, col.a);
                col.a *= smoothstep(_Unity, _ShortestUVMapping, i.uv2.x);
                return col;
            }
            ENDCG
        }
    }
}

2.创建材质
图中1的地方可选放不放图片
也可以texture tint color的地方改成自己想要的颜色

3.材质放到image上

4.设置值的方法

//x=0-1 float值
  imgPercent.material.SetFloat("_Unity", x/100f* 1.6f);