遮罩纹理（mask texture）控制光照的强度，获得更加细腻的效果，通过遮罩纹理控制光照。在制作地形材质的时候混合多张图片，遮罩纹理控制如何混合这些纹理。 通过采样得到的纹素值与某种表面属性相乘，来更加精准的控制模型表面的各种属性。 在代码中添加了BumpMap来进行凹凸纹理效果，通过SpecularMask实现控制高光的光照
代码语言：javascript复制Shader "Unlit/MaskTexture"
{
Properties{
_Color ("Color Tint",Color) = (1,1,1,1)
_MainTex("Main Tex",2D) = "white" {}
_BumpMap("Normal Map",2D) = "bump"{}
_BumpScale("Bump Scale",Float) = 1.0
_SpecularMask("Specular Mask",2D) = "white"{}
_SpecularScale("Specular Scale",Float) = 1.0
_Specular("Specular",Color) = (1,1,1,1)
_Gloss("Gloss",Range(8.0,256)) = 20
}
SubShader{
Pass{
Tags{ "LightMode" = "ForwardBase"}
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "Lighting.cginc"
fixed4 _Color;
sampler2D _MainTex;
float4 _MainTex_ST;
sampler2D _BumpMap;
float _BumpScale;
sampler2D _SpecularMask;
float _SpecularScale;
fixed4 _Specular;
float _Gloss;
struct a2v {
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 tangent : TANGENT;
float4 texcoord : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float3 lightDir : TEXCOORD1;
float3 viewDir : TEXCOORD2;
};
v2f vert(a2v v) {
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv.xy = v.vertex.xy * _MainTex_ST.xy _MainTex_ST.zw;
TANGENT_SPACE_ROTATION;
o.lightDir = mul(rotation, ObjSpaceLightDir(v.vertex).xyz);
o.viewDir = mul(rotation, ObjSpaceViewDir(v.vertex).xyz);
return o;
}
fixed4 frag(v2f i) :SV_Target{
fixed3 tangentLightDir = normalize(i.lightDir);
fixed3 tangentViewDir = normalize(i.viewDir);
fixed3 tangentNormal = UnpackNormal(tex2D(_BumpMap, i.uv));
tangentNormal.xy *= _BumpScale;
tangentNormal.z = sqrt(1.0 - saturate(dot(tangentNormal.xy, tangentNormal.xy)));
fixed3 albedo = tex2D(_MainTex, i.uv).rgb * _Color.rgb;
fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(tangentNormal, tangentLightDir));
fixed3 halfDir = normalize(tangentLightDir tangentViewDir);
fixed specularMask = tex2D(_SpecularMask, i.uv).r * _SpecularScale;
fixed3 specular = _LightColor0.rgb * specularMask * _Specular.rgb * pow(max(0, dot(halfDir, tangentNormal)), _Gloss);
return fixed4(ambient diffuse specular, 1.0);
}
ENDCG
}
}
}
MaskTexture.PNG
