Contrast ?

I have a solid with a small denivellement on surface.
I can’t visualize the depth, because it’s too small.

How might I do that?
I have tough to use the specular parameter of lighting. Is that the right way?

In fact, Specular has no incidence.
Is it a consequence of lighting in said position?
Has somebody an idea?

Thank you

Some code might help explain what you are trying to do. I don’t understand much of what you are asking, but I tell you a bit about how specular lighting works… You need to enable lighting, obviously. You also need to specify normals for your vertices. As the normal for the vertice gets closer to pointing back towards the viewer, you’ll end up getting more of the specular affecting it. The “shininess” of the material also affects this.