Quadraxas' response let me doubt that my answer was the appropriate.
You probably meant the very dark pic of the model, while I meant the pic of it in the left corner, because that appearance isn't common to the appearance of models within the engine.
If we are talking about the model in the left corner as well, and if that appearance is one within the engine, then there is something wrong with your model, I can assure you.
Acknex didn't invent the shading of the models anew, it is all the same directx stuff.
Even the vertex shading on the model in the dark part of the pic depends on the distribution of the polygons on the model's surface. This means you can improve the shading of the model without any shader.