We can't see anything without light. Nature have it own rules, 'natural rules' and to reproducing images or animations in 3d/2d space we need to know about the lighting basics; so that our creation in terms of image(s) looks closer to nature. Sometimes we view two colored image and believe them real and on the other side we see multimillion colored image and clearly say it FAKE. It hurts to hear it. Doesn't it!
So let's find out some mainly major or at least key points to not hear that word starting with F. To do so we need to have a clear understanding of the element related to this. To start with let's have two objects a sphere and a room, and we are in that room. We can't see anything unless we have a source of light. Just forget for a while about that we have sun or any other source of light. I will be indentifying the elements to learn by heart. Just forget for a while about that we have sun or any other source of light. I will be indentifying the elements to learn by heart.
1. For an object to be seen in this room let's bring some light. As we have introduced a light we can indentify two this in the above diagram.
a.Existence of the light on the floor
2. We just said that if there is no light we can't see anything so as the sphere is blocking the light to reach the floor, so that part will also be not visible.
And this thing is known as shadow and it's due to sphere that is cutting the light to reach the floor so it's sphere's shadow. It's also known as cast shadow.
Let's bring the light closer; as the light is closer you have notices that the shadow of sphere has become sharper. So, if light is near to the object its shadow will be hard edged [sharper].
Okay so we have got to know about shadows let's talk about colors, why we see a color?
3.Color derives from the spectrum of light (distribution of light energy versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. So let's place a pure blue sphere in the room.
Does it look natural? NO
We have; existence of the light on the floor, object, its shadow and color of course, so why it's not natural. If it's not then something is missing.
Let's go and find it!