A shader for showing progress in sin-wave style.

Shader Code:

Shader "Unlit/WaveProgress"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _Progress ("Progress", Range (0.0, 1)) = 0
    }
    SubShader
    {
        Tags { "RenderType"="Transparent" }
        LOD 100
        Blend SrcAlpha OneMinusSrcAlpha 

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
            uniform float _Progress;
            
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }
 

            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col = tex2D(_MainTex, i.uv);
                
                float sinWave = _Progress + (sin(i.uv.x * 6 + _Time.y * 4.7) +sin(i.uv.x * 8 + _Time.y * 5) + sin((i.uv.x - 0.003) * 7.5 + _Time.y * 5.3) )* 0.05;
                float pwidth = length(float2(ddx(i.uv.x), ddy(i.uv.y)));
                float wave = (1 + smoothstep(sinWave, sinWave - pwidth * 1.5, i.uv.y))/2;
                col.rgb = col.rgb * wave;
                return col;
            }
            ENDCG
        }
    }
}

More details

• How to create a vivid wave

float sinWave = _Progress + (sin(i.uv.x * 6 + _Time.y * 4.7) +sin(i.uv.x * 8 + _Time.y * 5) + sin((i.uv.x - 0.003) * 7.5 + _Time.y * 5.3) )* 0.05;

I used three sin functions to generate different waves with different parameters.

• How to do anti-aliasing
  • 1. use ddx and ddy to get the area of aliasing
  • 2. use smoothstep to lerp the sin wave edge for more smooth feeling.

float pwidth = length(float2(ddx(i.uv.x), ddy(i.uv.y)));
float wave = (1 + smoothstep(sinWave, sinWave - pwidth * 1.5, i.uv.y))/2;

• Composite all of these together for the final result.