Testing normal map texture setup on the gun scope model.
Top image showing the super fast Irrlicht realtime engine and below image is blender 3d glsl mode
Irrlicht diffuse and normal map is 1024x1024 and VBO geometry.
Obviously the buildt in irrlicht engine shaders is optimized for speed compared to blender glsl, but then again it lack some of the quality in blender viewport.
Hopefully some tweeking of  the light/specular setup in Irrlicht will make it better.