Cannot see letters graven in model

Hello,
I loaded an .stl model, in that model I have letters graven in it, but I cannot see these letters, do you think that it’s only a lights problem?
Does someone can help me?

Thank you

I loaded an .stl model, in that model I have letters graven in it, but I cannot see these letters, do you think that it’s only a lights problem?

The problem is probably that the letters are exactly the same color as the rest of the model. You must assign the polygons making up the letters a different color. This is most easily done with CAD (like Solid Works) or modeling (modo, maya, lightwave) software.

If the lettering is actually raised or etched into the model surface, then I’d say you have a lights problem. Are you using gl lighting?

Thank you for answer Carmine,
lettering is actually etched, and I’m trying to use modern OpenGL (GLSL and so on…)