I'm using OpenTK and working in C#, if that matters. I'm trying to get lighting effects on a textured object. I'm using obj and mtl files to define them. No matter what I try my object is either invisible, unlit (plain texture), or completely white.
I defined my mtl by having my texture mapped to diffusion (that is, map_Kd texture.png). I found that if I don't set both a Ka and Kd (in addition to the texture) the object is invisible. It also seems that the actual ambient values don't change anything - they could be 0 and transparent, as long as they're defined.
If I set my material to have white ambient, diffuse, and specular, then the object is 100% white, no matter what I do with my light source. And this is after I set it to gl_separate_specular_color, as before that I just got the plain texture. I tried making sure I had a normal defined for at least one face of the model, with no luck. I'm trying to have my texture be dominant, with a little bit of specular lighting on it.
What am I doing wrong? Is the lighting "working" but the all white means I haven't set my shininess properly? Is it being infinitely reflective or something?