2D and distortion shader

So im trying to make some sort of distortion. Everything looks fine with perspective camera,but doesnt work with 2D/ortographic camera.

Here`s my shader.

Code (CSharp):

1.  
2. Shader"Effects/Distortion/CullBack+1"{
3. Properties{
4. _Color("Main Color",Color)=(1,1,1,1)
5. _MainTex("Base (RGB) Gloss (A)",2D)="black"{}
6. _BumpMap("Normalmap",2D)="bump"{}
7. _ColorStrength("Color Strength",Float)=1
8. _BumpAmt("Distortion [0-100]", range (0,100))=10
9. }
10. SubShader{
11. Tags{"Queue"="Transparent+1""RenderType"="Transperent"}
12. GrabPass{}
13. LOD 200
14. ZWriteOn
15. CullBack
16. CGPROGRAM
17. #pragma surface surf Lambert alpha vertex:vert
18. sampler2D _MainTex;
19. sampler2D _BumpMap;
20. float_BumpAmt;
21. float_ColorStrength;
22. sampler2D _GrabTexture;
23. float4 _GrabTexture_TexelSize;
24. float4 _Color;
25. structInput{
26. float2 uv_MainTex;
27. float2 uv_BumpMap;
28. float4 proj : TEXCOORD0;
29. };
30. void vert (inout appdata_full v,outInput o){
31. UNITY_INITIALIZE_OUTPUT(Input,o);
32. float4 oPos = mul(UNITY_MATRIX_MVP, v.vertex);
33. #if UNITY_UV_STARTS_AT_TOP
34. float scale =-1.0;
35. #else
36. float scale =1.0;
37. #endif
38. o.proj.xy =(float2(oPos.x, oPos.y*scale)+ oPos.w)*0.5;
39. o.proj.zw = oPos.zw;
40. }
41. void surf (Input IN, inout SurfaceOutput o){
42. o.Normal=UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
43. half2 offset = o.Normal.rg *_BumpAmt*_GrabTexture_TexelSize.xy;
44. IN.proj.xy = offset * IN.proj.z + IN.proj.xy;
45. half4 col = tex2Dproj(_GrabTexture, UNITY_PROJ_COORD(IN.proj));
46. fixed4 tex = tex2D(_MainTex, IN.uv_MainTex)*_Color;
47. o.Emission= col.xyz + tex*_ColorStrength;
48. o.Alpha=_Color.a;
49. }
50. ENDCG
51. }
52. FallBack"Effects/Distortion/Free/CullBack"
53. }

2D/Ortograpic

Perscpective

 

Are you perhaps distorting in Z and now in X/Y?