People's skin is black, white and taupe, their clothes are in various colors, and their eyes are also divided into black, blue and yellow. In order to facilitate the matting, green is the best layout, which can make the decorative color of the set inconsistent with the color of the protagonist's clothes, but green is most easily recognized by matting software, which is convenient for automatically capturing the best image.

Not all of them are green. For example, the Youth School in Ang Lee is a blue screen. Because the water in the shooting pool is green, blue is easy to cut.

In short, the background with inconsistent colors is easy to compare the contours of people, and it is convenient to distinguish colors, but also for convenience. Because of the recognition rate of professional matting software such as mask pro, green occupies the narrowest color range and is the easiest to distinguish.

Cutout is the first step in the production of special effects, and then the model is added to increase the physical effect. Finally, layer by layer rendering. For example, add a lion next to the protagonist, first add a rough outline, then add bones, muscles and skin layer by layer, draw texture, add hair, and then calculate the stress and deformation of wind speed and water flow. Very complicated, almost all of them are manually rendered frame by frame.