Shader Instancing , no longer affected by directional ligth

Like mention in the title , i got this billboard shader but am enable to make the directionnal ligth work with instancing on. Do i need to make two pass?

Code (CSharp):

1.  
2.  
3. Shader "Billboard" {
4.  
5.     Properties
6.     {
7.         _Color("Color", Color) = (1,1,1,1)
8.         _Cutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
9.         _MainTex("Albedo Map", 2D) = "white" {}
10.         _BumpMap("Normal Map", 2D) = "bump" {}
11.         _BumpIntensity("NormalMap Intensity", Range(-1, 2)) = 1
12.         _BumpIntensity("NormalMap Intensity", Float) = 1
13.     }
14.      
15.     SubShader
16.     {
17.         Tags
18.         {
19.             "Queue" = "Transparent"
20.             "IgnoreProjector" = "True"
21.             "RenderType" = "TransparentCutout"
22.             "DisableBatching" = "True"
23.         }
24.  
25.         LOD 200
26.         Cull Off
27.         Lighting On
28.         ZWrite On
29.         Fog{ Mode Off }
30.  
31.  
32.         CGPROGRAM
33.         #pragma target 3.0
34.         #pragma surface surf Lambert alpha vertex:vert  alphatest:_Cutoff fullforwardshadows
35.         #pragma multi_compile DUMMY PIXELSNAP_ON
36.         #pragma exclude_renderers flash
37.         #define PI 3.1415926535897932384626433832795
38.         #define RAD2DEG 57.2957795131
39.         #define SINGLEFRAMEANGLE (360/1)
40.         #define UVOFFSETX (1/1)
41.  
42.         sampler2D _MainTex;
43.         sampler2D _BumpMap;
44.         fixed _BumpIntensity;
45.  
46.         UNITY_INSTANCING_CBUFFER_START(MyProperties)
47.             UNITY_DEFINE_INSTANCED_PROP(half4, _Color)
48.         UNITY_INSTANCING_CBUFFER_END
49.  
50.         float atan2Approximation(float y, float x) // http://http.developer.nvidia.com/Cg/atan2.html
51.         {
52.             float t0, t1, t2, t3, t4;
53.             t3 = abs(x);
54.             t1 = abs(y);
55.             t0 = max(t3, t1);
56.             t1 = min(t3, t1);
57.             t3 = float(1) / t0;
58.             t3 = t1 * t3;
59.             t4 = t3 * t3;
60.             t0 = -0.013480470;
61.             t0 = t0 * t4 + 0.057477314;
62.             t0 = t0 * t4 - 0.121239071;
63.             t0 = t0 * t4 + 0.195635925;
64.             t0 = t0 * t4 - 0.332994597;
65.             t0 = t0 * t4 + 0.999995630;
66.             t3 = t0 * t3;
67.             t3 = (abs(y) > abs(x)) ? 1.570796327 - t3 : t3;
68.             t3 = (x < 0) ? PI - t3 : t3;
69.             t3 = (y < 0) ? -t3 : t3;
70.             return t3;
71.         }
72.  
73.         struct Input
74.         {
75.             float4 pos : SV_POSITION;
76.             half2 uv : TEXCOORD0;
77.  
78.             float2 uv_MainTex;
79.             float2 uv_BumpMap;
80.             float2 uv_EmissionMap;
81.  
82.             UNITY_VERTEX_INPUT_INSTANCE_ID
83.         };
84.  
85.         void vert(inout appdata_full v, out Input o)
86.         {
87.             UNITY_INITIALIZE_OUTPUT(Input, o)
88.             UNITY_SETUP_INSTANCE_ID(v);
89.             UNITY_TRANSFER_INSTANCE_ID(v, o);
90.  
91.  
92.             // get the camera basis vectors
93.             float3 forward = -normalize(UNITY_MATRIX_V._m20_m21_m22);
94.             float3 up = normalize(UNITY_MATRIX_V._m10_m11_m12);
95.             float3 right = normalize(UNITY_MATRIX_V._m00_m01_m02);
96.  
97.             // rotate to face camera
98.             float4x4 rotationMatrix = float4x4(right, 0,
99.                 up, 0,
100.                 forward, 0,
101.                 0, 0, 0, 1);
102.  
103.             //float offset = unity_ObjectToWorld._m22 / 2;
104.             float offset = 0;
105.             v.vertex = mul(v.vertex + float4(0, offset, 0, 0), rotationMatrix) + float4(0, -offset, 0, 0);
106.             v.normal = mul(v.normal,rotationMatrix);
107.         }
108.  
109.         void surf(Input IN, inout SurfaceOutput o)
110.         {
111.             half4 albedo = tex2D(_MainTex, IN.uv_MainTex) *  UNITY_ACCESS_INSTANCED_PROP(_Color);
112.             o.Albedo = albedo.rgb;
113.             o.Alpha = albedo.a;
114.             o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
115.             _BumpIntensity = 1 / _BumpIntensity;
116.             o.Normal.z = o.Normal.z * _BumpIntensity;
117.             o.Normal = normalize((half3)o.Normal);
118.  
119.             UNITY_SETUP_INSTANCE_ID(IN);
120.         }
121.  
122.         half4 LightingSimpleLambert(SurfaceOutput s, half3 lightDir, half atten)
123.         {
124.             half4 c;
125.             c.rgb = s.Albedo * _LightColor0.rgb * (atten);
126.             c.a = s.Alpha;
127.             return c;
128.         }
129.  
130.         ENDCG
131.     }
132.         Fallback "Off"
133. }

Instancing OFF


Instancing ON