texture question

Hi All,
I have some difficulties trying to fix a texture that disappear when I rotate the 3D model. I'm testing with Standard Shader but I can't find the solution. If you look the model, half of the texture disappear with the rotation

Here some picture:

 

is that a brain?

is the texture one single thing or is it made up from several parts?

 

It has mainly two independent meshes (left and right)
I see that my problem is the shader in my background cube, but don't find the correct one. The idea is to have a background that give a sense of a space. Someone have a suggestion?
Thanks

 

can someone help me on this one?

Code (CSharp):

1.  
2. Shader"SimpleGlass" {
3. Properties {
4. _Color ("MainColor", Color) = (1,1,1,1)
5. _SpecColor ("SpecColor", Color) = (1,1,1,1)
6. _Emission ("EmmisiveColor", Color) = (1,1,0,0)
7. _Shininess ("Shininess", Range (0.01, 1)) = 0.21
8. _MainTex ("Base", 2D) = "white" { }
9.  }
10.  
11. SubShader {
12. //Weusethematerialinmanypassesbydefiningtheminthesubshader.
13. //Anythingdefinedherebecomesdefaultvaluesforallcontainedpasses.
14. Material {
15. Diffuse [_Color]
16. Ambient [_Color]
17. Shininess [_Shininess]
18. Specular [_SpecColor]
19. Emission [_Emission]
20.  }
21. LightingOn
22. SeparateSpecularOn
23.  
24. //Setupalphablending
25.  
26.  
27. //Renderthebackfacingpartsoftheobject.
28. //Iftheobjectisconvex, thesewillalwaysbefurtheraway
29. //thanthefront-faces.
30. Pass {
31. BlendSrcAlphaOneMinusSrcAlpha
32. Material {
33. Diffuse (0.1,0.1,0.1,1)
34.  }
35. CullFront
36. SetTexture [_MainTex] {
37. CombinePrimary * Texture
38.  }
39.  
40.  }
41. //Renderthepartsoftheobjectfacingus.
42. //Iftheobjectisconvex, thesewillbecloserthanthe
43. //back-faces.
44. Pass {
45. CullBack
46. BlendOneOne
47. SetTexture [_MainTex] {
48. CombinePrimary * Texture
49.  }
50.  }
51.  }
52. }
53. }

I'm trying with a simple shader but I can't find the solution yet