实现原理：

1.逐帧运动的图片切换实现闪电的效果

2.设置出发点，方向，长度实现两点的电流

实现代码：

1.逐帧动画

Shader实现:

Shader "Unlit/LightShader"
{
    Properties
    {
        _MainTint ("Diffuse Color", Color) = (1,1,1,1)           
        _MainTex("Base (RGB)",2D) = "white" {} 
        _TexWidth("Sheet Width",float) = 0.0    
        _SpriteFrameNum("Sprite Frame Counts",float) = 9.0  
        _Speed("Speed ",Range(0.01,32)) = 12  
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" "CanUseSpriteAtlas"="True"}
        LOD 200

        Pass
        {      
            Blend SrcAlpha One
            Cull Off Lighting Off ZWrite Off Fog { Color (0,0,0,0) }  
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
            fixed4 _MainTint;           
            float _TexWidth;            
            float _SpriteFrameNum;        
            float _Speed;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
            float2 spriteUV = i.uv;
            float uAddPerFrame = 1 / _SpriteFrameNum;      
            float timeVal = fmod(_Time.y * _Speed,_SpriteFrameNum); 
            timeVal = ceil(timeVal);
           
               
            float xValue = spriteUV.y;         
            xValue *= uAddPerFrame;                
            xValue += timeVal * uAddPerFrame; 
            spriteUV = float2(spriteUV.x,xValue);        
            fixed4 c = tex2D (_MainTex, spriteUV) * _MainTint;
            return c;
            }
            ENDCG
        }
    }
}

图片：

        public void ShowLight(Vector3 start,Vector3 end)
        {
            if (m_Parent == null)
            {
                m_Parent = SysManager.GetSys<FairyGUISys>(SysEnum.FairyGUISys).GetView<EffectView>(UIConfig.EffectView).FairyComponent;
            }
            float dis = (Vector3.Distance(start, end)*100)/25;//求长度
            float angle = GameUtlis.Angle(start, end);//求距离
            GameObject effect = m_LightEffectPool.GetObj(ResoursesConfig.LightUrl);//生成闪电特效
            SpriteRenderer spr = effect.GetComponent<SpriteRenderer>();
            spr.size = new Vector2(0, spr.size.y);
            DOTween.To(
                () => spr.size,
            a => { spr.size = a; },
            new Vector2(dis, spr.size.y),
            0.1F);
            effect.transform.position = start;
            effect.transform.eulerAngles = new Vector3(0,0,angle);
            effect.transform.parent = m_Parent.displayObject.gameObject.transform;
            effect.transform.localScale = new Vector3(50, 25, 1);
            SysManager.ObjectBase.StartCoroutine(GameUtlis.Wait(0.5f, () => {
                 DOTween.To(
                  () => spr.size,
                   a => { spr.size = a; },
                   new Vector2(0, spr.size.y),
                   0.3f).OnComplete(()=> {
                   m_ComBoEffectPool.RecycleObj(effect);
                   });
            }));
        }

方向算法：

       public static float Angle(Vector3 start,Vector3 end)
        {
            Vector3 target = end - start;
            float angle = Vector3.Angle(target, Vector3.right);
            if (target.y < 0)
            {
                angle = 360 - angle;
            }
            return angle;
        }