I have started another weapon, but I'm having flat shading problems. I use a basic method. Select all with the face selection tool, unweld vertex, uncheck auto smooth, weld vertexes together, then do tile texture mapper to planar, then export. But, when I do, some of the model turns black, but some parts of the model (Which all have the same texture) turn gray instead. The shading in-game looks terrible. It has too much shadow, and some of the curves are hardly visible.
How do I fix this?