Forwardadd Pass下的点光源光照的AlphaBlend贴图，呈现出了奇怪的像素

问题遇到的现象和发生背景 // Forwardadd Pass下的点光源光照的【透明度混合】（AlphaBlend）贴图，呈现出了奇怪的像素

用代码块功能插入代码，请勿粘贴截图

Properties
    {
        _Color ("Color Tint", Color) = (1, 1, 1, 1)
        _MainTex ("Main Tex", 2D) = "white" {}
        _BumpMap ("Normal Map", 2D) = "bump" {}
        _AlphaScale ("Alpha Value",Range(0.0 , 1.0)) = 1
    }
    SubShader {
        Tags { "RenderType"="Transparent" "IgnoreProjector" = "True" "Queue"="Transparent"}
        ZWrite Off    
        Pass { 
            Tags { "LightMode"="ForwardBase" }
            
            Blend SrcAlpha OneMinusSrcAlpha 
            CGPROGRAM
            
            #pragma multi_compile_fwdbase
            #pragma vertex vert
            #pragma fragment frag
            
            #include "Lighting.cginc"
            #include "AutoLight.cginc"
            
            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _BumpMap;
            float4 _BumpMap_ST;
            fixed _AlphaScale;
            
            struct a2v {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 tangent : TANGENT;
                float4 texcoord : TEXCOORD0;
            };
            
            struct v2f {
                float4 pos : SV_POSITION;
                float4 uv : TEXCOORD0;
                float4 TtoW0 : TEXCOORD1;  
                float4 TtoW1 : TEXCOORD2;  
                float4 TtoW2 : TEXCOORD3;
            };
            
            v2f vert(a2v v) {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                
                o.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                o.uv.zw = v.texcoord.xy * _BumpMap_ST.xy + _BumpMap_ST.zw;
                
                float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;  
                fixed3 worldNormal = UnityObjectToWorldNormal(v.normal);  
                fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);  
                fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w; 
                
                o.TtoW0 = float4(worldTangent.x, worldBinormal.x, worldNormal.x, worldPos.x);
                o.TtoW1 = float4(worldTangent.y, worldBinormal.y, worldNormal.y, worldPos.y);
                o.TtoW2 = float4(worldTangent.z, worldBinormal.z, worldNormal.z, worldPos.z);  
                
                return o;
            }
            
            fixed4 frag(v2f i) : SV_Target {
                float3 worldPos = float3(i.TtoW0.w, i.TtoW1.w, i.TtoW2.w);
                fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos));
                fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos));
                
                fixed3 bump = UnpackNormal(tex2D(_BumpMap, i.uv.zw));
                bump = normalize(half3(dot(i.TtoW0.xyz, bump), dot(i.TtoW1.xyz, bump), dot(i.TtoW2.xyz, bump)));
                
                fixed3 albedo = tex2D(_MainTex, i.uv.xy).rgb * _Color.rgb;
                
                fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
            
                 fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(bump, lightDir));
                
                UNITY_LIGHT_ATTENUATION(atten, i, worldPos);

                fixed4 texColor = tex2D(_MainTex, i.uv);

                return fixed4(ambient + diffuse * atten, texColor.a * _AlphaScale);
            }
            ENDCG
        }
        
        Pass { 
            Tags { "LightMode"="ForwardAdd" }
            
            Blend One One
            
            CGPROGRAM
            
            #pragma multi_compile_fwdadd
           
             #pragma vertex vert
            #pragma fragment frag
            
            #include "Lighting.cginc"
            #include "AutoLight.cginc"
            
            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _BumpMap;
            float4 _BumpMap_ST;
            
            struct a2v {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 tangent : TANGENT;
                float4 texcoord : TEXCOORD0;
            };
            
            struct v2f {
                float4 pos : SV_POSITION;
                float4 uv : TEXCOORD0;
                float4 TtoW0 : TEXCOORD1;  
                float4 TtoW1 : TEXCOORD2;  
                float4 TtoW2 : TEXCOORD3;
               
            };
            
            v2f vert(a2v v) {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                
                o.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                o.uv.zw = v.texcoord.xy * _BumpMap_ST.xy + _BumpMap_ST.zw;
                
                float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;  
                fixed3 worldNormal = UnityObjectToWorldNormal(v.normal);  
                fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);  
                fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w; 
                
                o.TtoW0 = float4(worldTangent.x, worldBinormal.x, worldNormal.x, worldPos.x);
                o.TtoW1 = float4(worldTangent.y, worldBinormal.y, worldNormal.y, worldPos.y);
                o.TtoW2 = float4(worldTangent.z, worldBinormal.z, worldNormal.z, worldPos.z);  
                
                return o;
            }
            
            fixed4 frag(v2f i) : SV_Target {
                float3 worldPos = float3(i.TtoW0.w, i.TtoW1.w, i.TtoW2.w);
                fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos));
                fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos));
                
                fixed3 bump = UnpackNormal(tex2D(_BumpMap, i.uv.zw));
                bump = normalize(half3(dot(i.TtoW0.xyz, bump), dot(i.TtoW1.xyz, bump), dot(i.TtoW2.xyz, bump)));
                
                fixed3 albedo = tex2D(_MainTex, i.uv.xy).rgb * _Color.rgb;
                
                 fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(bump, lightDir));
                
                UNITY_LIGHT_ATTENUATION(atten, i, worldPos);
                
                return fixed4(diffuse * atten, 1.0);
            }
            ENDCG
        }
    } 

运行结果及报错内容 //无报错

我想要达到的结果