Shader "Custom/Shader1" { Properties { _MainTex ("Base (RGB)", 2D) = "white" {} _Bump ("Bump", 2D) = "bump" {} _Snow ("Snow Level", Range(0,1) ) = 0 _SnowColor ("Snow Color", Color) = (1.0,1.0,1.0,1.0) _SnowDirection ("Snow Direction", Vector) = (0,1,0) _SnowDepth ("Snow Depth", Range(0,0.3)) = 0.1 } SubShader { Tags { "RenderType"="Opaque" } LOD 200 CGPROGRAM #pragma surface surf CustomDiffuse vertex:vert sampler2D _MainTex; sampler2D _Bump; float _Snow; float4 _SnowColor; float4 _SnowDirection; float _SnowDepth; struct Input { float2 uv_MainTex; //3 float2 uv_Bump; float3 worldNormal; INTERNAL_DATA }; void surf (Input IN, inout SurfaceOutput o) { half4 c = tex2D (_MainTex, IN.uv_MainTex); o.Normal = UnpackNormal(tex2D(_Bump, IN.uv_Bump)); if (dot(WorldNormalVector(IN, o.Normal), _SnowDirection.xyz) > lerp(1,-1,_Snow)) { o.Albedo = _SnowColor.rgb; } else { o.Albedo = c.rgb; } o.Alpha = c.a; } inline float4 LightingCustomDiffuse (SurfaceOutput s, fixed3 lightDir, fixed atten) { float difLight = max(0, dot (s.Normal, lightDir)); float hLambert = difLight * 0.5 + 0.5; float4 col; col.rgb = s.Albedo * _LightColor0.rgb * (hLambert * atten * 2); col.a = s.Alpha; return col; } void vert (inout appdata_full v) { float4 sn = mul(transpose(_Object2World) , _SnowDirection); if(dot(v.normal, sn.xyz) >= lerp(1,-1, (_Snow * 2) / 3)) { v.vertex.xyz += (sn.xyz + v.normal) * _SnowDepth * _Snow; } } ENDCG } FallBack "Diffuse" }
通过以上shader可以实现在石头上叠加积雪的效果,_SnowDepth为积雪的厚度,这个shader也能实现其他一些类似的效果(如灰尘的堆积)。