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

Question

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

Answer 1

Unity Shader入门精要学习笔记 - 第9章 更复杂的光照_锐萌瑞的博客-CSDN博客 转载自 冯乐乐的《Unity Shader入门精要》Unity 的渲染路径在Unity里，渲染路径决定了光照是如何应该到Unity Shader 中的。因此，如果要和光源打交道，我们需要为每个Pass指定它使用的渲染路径，只有这样才能让Unity知道，“哦，原来这个程序想要这种渲染路径，那么好的，我把光源和处理后的光照信息都放在这些数据里，你可以访问啦！”也就是说，我们只有为Shader 正确地选... https://blog.csdn.net/qq_34552886/article/details/81005664?ops_request_misc=&request_id=&biz_id=102&utm_term=Forwardadd%20Pass%E4%B8%8B%E7%9A%84%E7%82%B9%E5%85%89%E6%BA%90%E5%85%89%E7%85%A7%E7%9A%84AlphaBl&utm_medium=distribute.pc_search_result.none-task-blog-2~all~sobaiduweb~default-0-81005664.142^v63^js_top,201^v3^control_1,213^v2^t3_esquery_v3&spm=1018.2226.3001.4187