Shader "Custom/FlowColor" {
	Properties {
		_MainTex ("Base (RGB)", 2D) = "white" {}
		_FlowColor("Flow Color", Color) = (1,1,1,1)
		_FlowRange("Flow Range", Float) = 0.01
	}

	SubShader {

		
		Pass
        {

		Tags {   "Queue" = "Geometry" }

		CGPROGRAM

        #include "UnityCG.cginc"

		struct v2f
		{
			float4 vertex:POSITION;
			float2 uv:TEXCOORD0;
			float nr:TEXCOORD1;
		};

		sampler2D _MainTex;
		float4 _FlowColor;
		float _FlowRange;

		v2f vert(appdata_base  v)
		{
			
			v2f o;
			o.uv = v.texcoord;
			o.vertex = mul(UNITY_MATRIX_MVP,v.vertex);
			float2 dir = normalize(float2(cos(_Time.y),sin(_Time.y)));
			float2 worldNormal = normalize(mul((float3x3)_Object2World,v.normal)).xz;
			
			o.nr = dot(dir,worldNormal);
						

			return o;
		}

		fixed4 frag (v2f IN):COLOR
		{
			//fixed4  c = tex2D(_MainTex, IN.uv);
			fixed fac = saturate(sign(IN.nr *(IN.nr-_FlowRange)));
			fixed4 c=fac*tex2D(_MainTex, IN.uv) +(1-fac)*_FlowColor;
			return c;
		}

        #pragma vertex vert
        #pragma fragment frag

		ENDCG
		}

		
	} 
	FallBack "Diffuse"
}

Unity Shader 模型流光效果