“主角光环”

实现了基础的圆形遮罩；灯塔使用MagicaVoxel搭建，模仿光柱追踪效果（虽然灯塔本身导入后似乎没有发光效果

脚本部分核心代码（与教材同）：

#region 圆环内容
        radiusMaterial.SetVector("_Center", transform.position);
        radiusMaterial.SetColor("_RadiusColor", color);
        radiusMaterial.SetFloat("_Radius", radius);
#endregion

shader部分核心代码：

//圆环------
            //最后再进行圆环的处理，直接覆盖在原有的地表
            float d = distance(_Center, IN.worldPos);
            if(d<_Radius)  
            {
            	//在半径内的区域显示指定环贴图部分；半径外为地表部分
                finalColor = radiusTex.rgb * _RadiusColor;
            }
            o.Albedo = finalColor;
            o.Alpha = 1;

完整shader代码：

Shader "Custom/sd_snow"
{
    Properties
    {
        _MainColor("Main Color", Color) = (1,1,1,1)
        _MainTex("Base(RGB)",2D) = "white"{}
        _Bump("Bump", 2D) = "bump"{}
        _Level("Level of Snow", Range(0,1)) = 0.2
        _SnowDepth("Depth of Snow",Range(0,1)) = 0.3
        _SnowDirection("Direction of Snow",Vector) = (0,1,0)

        //角色圆环
        _Center("Center", Vector) = (0,0,0,0)   //player位置
        _Radius("Radius", Float) = 0.5          //图案半径
        _RadiusColor("Radius Color", Color) = (1,0,0,1)     //图案染色
        _RadiusTex("Radius Tex", 2D) = ""{}                 //图案贴图
        
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        #pragma surface surf Standard vertex:vert
        #pragma target 3.0

        sampler2D _MainTex;
        sampler2D _Bump;
        sampler2D _RadiusTex;
        struct Input
        {
            float2 uv_MainTex;
            float2 uv_Bump;
            float3 worldNormal;
            INTERNAL_DATA
            float2 uv_RadiusTex;
            float3 worldPos;
        };
        fixed4 _MainColor;
        float _SnowDepth;
        fixed _Level;
        float4 _SnowDirection;
        //圆环
        float3 _Center;
        float _Radius;
        float3 _RadiusColor;

        UNITY_INSTANCING_BUFFER_START(Props)
        UNITY_INSTANCING_BUFFER_END(Props)

        void surf (Input IN, inout SurfaceOutputStandard o)
        {
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex);
            fixed3 radiusTex = tex2D(_RadiusTex, IN.uv_RadiusTex).rgb;  //圆环图案
            float3 finalColor;

            //雪
            if(dot(WorldNormalVector(IN, o.Normal),_SnowDirection.xyz) >= (1 - _Level))
            {
                //有雪的情况
                finalColor = _MainColor;
                o.Normal = UnpackNormal(tex2D(_Bump, IN.uv_Bump));;
            }
            else
                finalColor = c.rgb;

            //圆环------
            //最后再进行圆环的处理，直接覆盖在原有的地表
            float d = distance(_Center, IN.worldPos);
            if(d<_Radius)  
            {
                //在半径内的区域显示指定环贴图部分；半径外为地表部分
                finalColor = radiusTex.rgb * _RadiusColor;
            }
            o.Albedo = finalColor;
            o.Alpha = 1;
        }

        void vert(inout appdata_full v)
        {
            float4 sn = mul(UNITY_MATRIX_IT_MV, _SnowDirection);
            if(dot(v.normal, sn.xyz)>=_Level)
            v.vertex.xyz += (sn.xyz + v.normal) * _SnowDepth * _Level;
        }
        ENDCG
    }
    FallBack "Diffuse"
}