I like to sketch. I'm not very good, but I enjoy it. I can copy from a drawing, I can copy a photograph, but I can't draw something in front of me! Give me a photo and I can redraw it with the right proportions and block the dark/light areas, but I can't do the same with a real object. It's like my brain can't translate a 3D picture into 2D.
Is there a book or online resource that can help? Or does anyone have any suggestions on what I'm doing wrong?