If black is absorptive and shiny means reflective, how can anything be both at once? I’m thinking of things like polished black marble, polished coal (jet) and shiny black cars. If they absorbs some light and reflects some, why aren’t they gray? Okay, I know that things that look black usually reflect a little light, whether they’re shiny or not. But here in front of me I have a black matte book cover and a shiny black notebook. Side-by-side, the shiny notebook actually looks darker. What gives? I did study optics in college Physics III, but this topic never came up.
Black would be the color, but if the texture of the object is polished and smooth say like metal then it’ll be reflective. I think the roughness determines its shininess and color determines how much light is absorbed after the texture layer.
In the super-simple lighting model that is often used in computer graphics, which was based on plastics, heres how it works:
You shine a light on a green plastic ball. Some light hits the smooth surface of the ball, bounces off in a nice way, and you get a reflection of the light (the rougher the surface, the less nice the reflection of the light is, so your reflection spreads out into specular highlights on the ball). The way the reflection/highlight looks depends on the angle you view the object at.
Some light goes through the surface, hits the little green pigment chips embedded in the plastic, and gets scattered in all directions. The way these outgoing scattered rays look don’t depend on your angle, so this gives the object its overall color.
So in your example of the car, you have the paint base, which is clear and smooth, and will reflect the light, and then the paint pigment which absorbs all the rest of the light.