Drawing 3D

Perspective, or angles between the lines lends the illusion of depth. With perspective, 3D object can be depicted in 2D screen.

When one covers one eye and looks, the world still appears as in 3D because perspective alone is enough to create the 3D effect. Another obvious clue is nearby objects appear larger than the distant ones. This perspective effect is called foreshortening.

To enhance 3D effect in drawing on 2D, another technique is to remove hidden lines and surfaces from the object on screen. Applying different color to different side of object simulates the effects of light. Adding shadow further enhances the illusion.

Texture mapping takes an image, such as a photo and applies it on the surface of an object to give it a realistic looks. For example, applying wood texture onto a cube to make it looks like a box. The process of stretching and compressing texels (texture elements) is called filtering.

Fog adds haziness to objects in a scene depending on the distance where objects are.

Blending is the combination of colors or objects on the screen, similar to superimposing 2 images. By varying the amount of each object with the scene, one can make the effect of transparency. Blending can create the illusion of reflection.

Antialiasing blends the lines with the background color to eliminate the jagged edges.