【UnityShdaer入门精要】RampTexure 渐变纹理

常用来干什么？

• 拿来控制漫反射光照的结果
• 风格化渲染 如卡通风格渲染

效果

  拿一张渐变纹理贴图控制漫反射的结果，在如下贴图的效果下明暗效果变化呈现块状：在块儿内的梯度小，块儿内的梯度大。

  最终呈现的效果类似于风格化渲染，这里想卡通渲染。

key

            fixed halfLambelt = 0.5 * dot(worldNormal , worldLightDir) + 0.5;
            //在渐变纹理上采样（x,x)的点作为漫反射的反射率 手动控制光照
            fixed3 diffuseColor = tex2D(_RampTex, fixed2(halfLambelt, halfLambelt)).rgb * _Color.rgb;

代码

Shader "Unlit/RampTexure"
{
    Properties
    {
        _Color ("Color Tint",Color) = (1,1,1,1)
        _RampTex ("Ramp Tex", 2D) = "white" {}
        _Specular("Specular",Color) = (1,1,1,1)
        _Gloss("Gloss", Range(8.0,256)) = 20
    }
    SubShader
    {
        Pass
        {
        Tags { "RenderType" = "ForwardBase" }
        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag


        #include "UnityCG.cginc"
        #include "Lighting.cginc"

        fixed4 _Color;
        sampler2D _RampTex;
        float4 _RampTex_ST;
        fixed4 _Specular;
        float _Gloss;

        struct appdata
        {
            float4 vertex : POSITION;
            float4 uv : TEXCOORD0;
            float3 normal : NORMAL;
        };

        struct v2f
        {
            float2 uv : TEXCOORD2;
            float4 vertex : SV_POSITION;
            float3 worldNormal : TEXCOORD0;
            float3 worldPos : TEXCOORD1;
        };


        v2f vert (appdata v)
        {
            v2f o;
            o.vertex = UnityObjectToClipPos(v.vertex);
            o.worldNormal = UnityObjectToWorldNormal(v.normal);
            o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;

            o.uv = TRANSFORM_TEX(v.uv, _RampTex);
            return o;
        }

        fixed4 frag(v2f i) : SV_Target
        {
            fixed3 worldNormal = normalize(i.worldNormal);
            fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos)); 

            fixed ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
                
            fixed halfLambelt = 0.5 * dot(worldNormal , worldLightDir) + 0.5;
            //在渐变纹理上采样（x,x)的点作为漫反射的反射率 手动控制光照
            fixed3 diffuseColor = tex2D(_RampTex, fixed2(halfLambelt, halfLambelt)).rgb * _Color.rgb;

            fixed3 diffuse = _LightColor0.rgb * diffuseColor;

            fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));
            fixed3 halfDir = normalize(worldLightDir + viewDir);
            fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0, dot(worldNormal, halfDir)), _Gloss);
            // sample the texture
               
            return fixed4(ambient + diffuse + specular,1.0);
        }
        ENDCG
    }
    }
    Fallback "Specular"
}