效果图片

靠近墙壁

远离墙壁
材质球的设置

两张图片

使用方式
把这个脚本放到墙上，将player赋值给"_player"，然后运行，用户靠近就会根据距离显示光墙。

using UnityEngine;

public class NewBehaviourScript : MonoBehaviour
{
    private Material _mat;
    public GameObject _player;

    private void Start()
    {
        _mat = gameObject.GetComponent<MeshRenderer>().materials[0];
        Debug.Log(_player.transform.position);
    }

    private void Update()
    {
        _mat.SetVector("_PlayerPos", _player.transform.position);
    }
}

shader代码

Shader "Unlit/NewUnlitShader"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
_MulTex ("MulTex",2D)="White" {}
         _Color ("Color",Vector)=(1,1,1,0)
        _PlayerPos("PlayerPos",Vector)=(1,1,1,0)
        _EdgeRange("EdgeRange",Vector)=(2,6,0,0)
_uvSpeed("uvSpeed",vector)=(1,0,0,0)
    }
    SubShader
    {
        Tags { "RenderType"="Transparent" "Queue"="Transparent" }
       Blend  SrcAlpha OneMinusSrcAlpha
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
    float2 uv2:TEXCOORD2;
            };
            struct v2f
            {
                float2 uv : TEXCOORD0;
float2 uv2:TEXCOORD2;
                float4 vertex : SV_POSITION;
                float4 vertexWorldPos : TEXCOORD1;
            };
            sampler2D _MainTex;
            sampler2D _MulTex;
            float4 _MainTex_ST;
            float4 _MulTex_ST;
            float4 _PlayerPos;
            float4 _EdgeRange;
float4 _uvSpeed;
float4 _Color;
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                o.uv2 = TRANSFORM_TEX(v.uv2, _MulTex);
o.uv2+=_Time.x*_uvSpeed;
                o.vertexWorldPos= mul(unity_ObjectToWorld,v.vertex);
                return o;
            }
            fixed4 frag (v2f i) : SV_Target
            {
float dis=abs(distance(i.vertexWorldPos,_PlayerPos));
float4 tex=tex2D(_MainTex,i.uv);
float4 tex2=tex2D(_MulTex,i.uv2);
float4 color1=_Color;
                tex.a*= 1 - smoothstep(_EdgeRange.x,_EdgeRange.y,dis);
                fixed4 col = tex2D(_MainTex, i.uv);
                return tex*color1*tex2;
            }
            ENDCG
        }
    }
}

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