How to get pixel normal in surface shader

This seems quite basic, but I'm having trouble getting the perturbed pixel normal in a surface shader. I've looked at the docs and example shaders, but my results still seem curious. Consider the following surf function. Its supposed to be a flat normal map, and then the dot product of the view dir and surface normal.

Code (CSharp):

1. void surf (Input IN, inout SurfaceOutputStandardSpecular o) {
2.     o.Normal = half3(0, 0, 1);
3.     float3 n = WorldNormalVector (IN, o.Normal);
4.  
5.     o.Emission = dot(IN.viewDir, n);
6.     o.Albedo = 0;
7.     o.Specular = 0;
8. }

The result of that shader is the sphere on the left, but I'd expect something like the sphere on the right. What am I doing wrong?

 

I believe for surface shaders IN.viewDir is in tangent space, so try dot(IN.viewDir, o.Normal)

 

That was exactly it! Thanks so much! Would have never tried that, haha. Seems so natural to me that the view direction would be in world space.