复杂纹理复制及纹理叠加效果

三张贴图通过改变主材质及修饰材质的UV重复次数，实现不同的效果。如下：

图中的房子和围墙只用了三张贴图就实现了完全不同的建筑，厉害吧~~~

shader如下：

Properties
    {
        _Color("Base Color", Color) = (1,1,1,1)
        _MainTex("Base(RGB)", 2D) = "white" {}
        _ColorU("ColorU", float) = 1.0 //主纹理X轴重复次数
        _ColorV("ColorV", float) = 1.0 //主纹理Y轴重复次数
        _DetailTex("DetailTex", 2D) = "white" {}
        _DetailU("DetailU", float) = 1.0 //修饰纹理X轴重复次数
        _DetailV("DetailV", float) = 1.0 //修饰纹理Y轴重复次数
    }
    
    SubShader
    {
        tags{"Queue" = "Transparent" "RenderType" = "Transparent" "IgnoreProjector" = "True"}
        Blend SrcAlpha OneMinusSrcAlpha
        
        Pass
        {
            
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            
            float4 _Color;
            sampler2D _MainTex;
            float _ColorU;
            float _ColorV;
            sampler2D _DetailTex;
            float _DetailU;
            float _DetailV;
            
            struct v2f
            {
                float4 pos:POSITION;
                float2 uv:TEXCOORD0;
            };
            
            
            float4 _DetailTex_ST;
            v2f vert(appdata_base v)
            {
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                o.uv = v.texcoord.xy;
                //o.uv = TRANSFORM_TEX(v.texcoord, _DetailTex);//简单的UV重复，通过界面的Tiling属性改变UV的重复次数，Offset改变UV位置。
                return o;
            }
            
            half4 frag(v2f i):COLOR
            {    
                half4 c = tex2D(_MainTex , i.uv * float2(_ColorU, _ColorV)) * _Color;
                half4 d = tex2D(_DetailTex, i.uv * float2(_DetailU, _DetailV));
                return c * d;
            }
            
            ENDCG
        }
    }