Neverwinter Nights 2 uses a rendering technique called normal mapping, taking bump-mapping to another level where you apply the details of a high polygon model onto a low polygon model. The reason it is called normal mapping is it takes the X, Y, Z direction of a polygon's normal and creates an RGB image, which is used to define which direction on the model the polygon will face. Then, when rendering using per-pixel shading, it will adjust the lighting on the low-poly model, creating the illusion there is more detail than there really is. ( hi / low res example )