Shader "Unlit/ScrollBackMat" { Properties { _OneTex ("OneTex", 2D) = "white" {} _TwoTex("TwoTex",2D) = "white" {} _OneSpeed("OneSpeed",Float) = 1.0 _TwoSpeed("TwoSpeed",Float) = 1.0 _Multiplier("Layer Multiplier",Float) = 1 } SubShader { Tags { "RenderType"="Opaque" } LOD 100 Pass { CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float4 uv : TEXCOORD0; float4 vertex : SV_POSITION; }; sampler2D _OneTex; float4 _OneTex_ST; sampler2D _TwoTex; float4 _TwoTex_ST; float _OneSpeed; float _TwoSpeed; float _Multiplier; v2f vert (appdata v) { v2f o; o.vertex = UnityObjectToClipPos(v.vertex); o.uv.xy = TRANSFORM_TEX(v.uv, _OneTex) + frac(float2(_OneSpeed,0.0) * _Time.y); o.uv.zw = TRANSFORM_TEX(v.uv, _TwoTex) + frac(float2(_TwoSpeed, 0.0) * _Time.y); return o; } fixed4 frag (v2f i) : SV_Target { fixed4 one = tex2D(_OneTex, i.uv.xy); fixed4 two = tex2D(_TwoTex, i.uv.zw);//靠前的那张背景图,有透明 fixed4 col = lerp(one, two, two.a);//非透明部分1显示two,透明部分0显示one col.rgb *= _Multiplier;//亮度的调整 return col; } ENDCG } } }
frac函数是获取取的x值的小数部分,效果: