I'm new at OpenTK and am using it with VB.Net. So far everything has worked well and performance is good, except that I can't get diffuse lighting to shade my objects (crude vehicles moving on a highway). The only light source that works is ambient. I have tried a variety of options for setting the light and materials in the Form_Load event, and the results in the attached screenshot are with the lines shown as commented out (I have tried all combinations without much difference).

Currently its a bit dark since the ambient values are turned down.

A timer drives movement of the camera and vehicles along the road.

I would also appreciate any critique of my code organization.

A screenshot and my code are attached.

Thank you!

[attachment=18015:Highway.jpg]

[attachment=18016:VB Code for OpenTK.txt]