Learning OpenGL: (1) concept of 3D

1. Which 3D

The term three-dimension, or 3D, means that an object being described or displayed has three dimension of measurement:Width,Height, AndDepth.

 

 

2. True 3D

To truly see in 3D, You need to actually view an object with both eyes.

The brain combines these slightly different images to produce a single, composite 3D picture in your head.

 

 

3. Approximation 3D

The reason the world doesn't suddenly look flat when you cover one eye is that pretty 3D effects are still present when viewed two-dimensionally.

 

One clue is surface shading due to lighting, another is that near by objects appear larger than distant objects. the perspective effect is called foreshortening. this effect and color changes, textures, shading, variations of color intensities together add up to our perception of a three-dimen1_image.

 

Look: