利用LineRenderer组件设计导航箭头。

1.Shader

//导航箭头
Shader "Custom/NavPathArrow"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _ScrollXSpeed("X Scroll Speed", Range(-20, 20)) = 2
        _ScrollYSpeed("Y Scroll Speed", Range(-20, 20)) = 2
    }
    SubShader
    {
        //Overlay、Transparent
        Tags { "Queue" = "Overlay" "RenderType"="Overlay" "IgnoreProjector" = "True" "PreviewType" = "Plane" }
        LOD 100
        //双面渲染
        Cull Off
        //关闭光照
        Lighting Off
        //关闭深度写入
        ZWrite Off
        //开启深度测试
        ZTest Always
        //Alpha混合
        Blend SrcAlpha OneMinusSrcAlpha
 
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
 
            #include "UnityCG.cginc"
 
            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };
 
            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };
 
            sampler2D _MainTex;
            float4 _MainTex_ST;
            half _ScrollXSpeed;
            half _ScrollYSpeed;
 
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }
 
            fixed4 frag(v2f i) : SV_Target
            {
                fixed2 uv = i.uv;
                fixed t = frac(_Time.y);//[0,1)
                uv.x += _ScrollXSpeed * t;
                uv.y += _ScrollYSpeed * t;
                fixed4 col = tex2D(_MainTex, uv);
                return col;
            }
            ENDCG
        }
    }
}

2.C#脚本

using System.Collections.Generic;
using UnityEngine;
/// <summary>
/// 导航箭头
/// </summary>
public class NavPathArrow : MonoBehaviour
{
    [SerializeField]
    private LineRenderer lineRenderer;
    [SerializeField]
    private int lineWidth = 5;
    [SerializeField]
    private List<Transform> points = new List<Transform>();
    private List<Vector3> vectors = new List<Vector3>();

    private void Awake()
    {
        lineRenderer.alignment = LineAlignment.View;
        lineRenderer.textureMode = LineTextureMode.Tile;
        lineRenderer.startWidth = lineWidth;
        lineRenderer.endWidth = lineWidth;
    }

    // 绘制路径
    private void DrawPath()
    {
        vectors.Clear();
        points.ForEach(p => { 
            if (p.gameObject.activeInHierarchy)
                vectors.Add(p.position); 
        });

        if (vectors.Count != lineRenderer.positionCount)
            lineRenderer.positionCount = vectors.Count;

        for (int i = 0; i < vectors.Count; i++)
            lineRenderer.SetPosition(i, vectors[i]);
    }

    private void Update()
    {
        DrawPath();
    }
}

运行效果