unity3d - Unity Shader: Deform a 3D model using vertex shader then apply specular using surface shader -

i need in applying specular shade in 3d model after deformed in cg vertex shader. don't know how in unity shader. searched in google , there no hits of looking for.

below current solution. 3d object rendered twice.

    shader "myshader/deformspecular" {     properties {             _color ("main color", color) = (1,1,1,0.5)             _shininess ("shininess", range (0.01, 1)) = 0.7             _maintex ("base (rgb)", 2d) = "white" { }             _bumpmap ("normalmap", 2d) = "bump" {}             _cubesize("cube size", range (1, 10)) = 1           }          subshader {              tags { "rendertype"="opaque" }             lod 250              pass{                 cgprogram                 #pragma vertex vert                 #pragma fragment frag                  #include "unitycg.cginc"                 #include "myshaderfuncs.cginc"                  sampler2d _maintex;                 sampler2d _bumpmap;                 half _shininess;                  float4 _color;                 float4x4 _localorient;  //local orientation                  float4x4 _parentworient;  //world orientation of parent node                 float _deformparam;                  struct v2f {                     float4  pos : sv_position;                     float2  uv : texcoord0;                 };                   float4 _maintex_st;                  v2f vert (appdata_base v)                 {                       v2f o;                        o.pos = mul(_localorient, v.vertex); //apply local transformation                      o.pos = deformshape(_deformparam);   //apply deform                      o.pos = mul(_parentworient, o.pos);  //apply parents world orientation                     o.pos = mul (unity_matrix_vp, o.pos);                     o.uv = transform_tex (v.texcoord, _maintex);                     return o;                 }                   half4 frag (v2f i) : color                 {                     half4 texcol = tex2d (_maintex, i.uv);                     return texcol * _color;                 }                  endcg               }//pass              cgprogram             #pragma surface surf mobileblinnphong exclude_path:prepass nolightmap noforwardadd halfasview              inline fixed4 lightingmobileblinnphong (surfaceoutput s, fixed3 lightdir, fixed3 halfdir, fixed atten)             {                 fixed diff = max (0, dot (s.normal, lightdir));                 fixed nh = max (0, dot (s.normal, halfdir));                 fixed spec = pow (nh, s.specular*128) * s.gloss;                  fixed4 c;                 c.rgb = (s.albedo * _lightcolor0.rgb * diff + _lightcolor0.rgb * spec) * (atten*2);                 c.a = 0.0;                 return c;             }              sampler2d _maintex;             sampler2d _bumpmap;             half _shininess;              struct input {                 float2 uv_maintex;             };              void surf (input in, inout surfaceoutput o) {                 fixed4 tex = tex2d(_maintex, in.uv_maintex);                 o.albedo = tex.rgb;                 o.gloss = tex.a;                 o.alpha = tex.a;                 o.specular = _shininess;                 o.normal = unpacknormal (tex2d(_bumpmap, in.uv_maintex));             }             endcg          }//subshader          fallback "mobile/vertexlit"     } 

if understood correctly, want specular lighting calculations inside cg shader?

unity gives lighting info can access own calculations if wish:

http://docs.unity3d.com/documentation/components/sl-builtinvalues.html

however, doc seems outdated , variables wrong point out here:

http://answers.unity3d.com/questions/411114/shaderlab-builtin-lighting-properties-are-not-corr.html

once use these variables can calculate lighting want