Normal Mapping: ITS ALL A LIE!!!

Normal Mapping is quite an interesting feature that an individual can implement on their models.  Normal mapping is used to imitate a high resolution geometry detail, when really the geometry is of a low resolution.  In a way, normal mapping is a certain way to implement a style of bump mapping onto the model in a scene. It is quite useful tool since it can greatly enhance the appearance of a low polygon model, making it look as though it is constructed from thousands of polygons, when really it may only be in the hundreds.

An example of Normal Mapping

There is a difference when it comes to Normal mapping as there are two different ways to normal mapping. The first of the two types is Object space Normal mapping.  The pros and cons of this style of mapping is:

Pro's

       -  The curvature of the object is very high quality because the low poly vertex normal's are easy to ignore

       - Slight better performance compared to Tangent mapping

Con's 

        - Do not compress very well since the  blue channel cannot be recreated.

        - Harder to overlay painted details since the base colors vary.

        -  Reusing maps is difficult. This is because different mesh shapes require unique maps.

Tangent Space Normal Mapping: 

Pro's: 

        -  Image compression is much easier

        - Maps can be easily reused on different shaped meshes. 

        - Easier to overlay painted details when texturing the objects

Con's 

        - The performance is slightly slower in comparison to Object-Space.

         - Problems often arise with smoothing from low poly normals. 

Before and After Normal Mapping