What is the rendering and contrast in the novel?

Rendering and contrast are often involved in poetry appreciation. Rendering aims to highlight the image and express the center through the description, description and modification of the environment, character behavior and psychology. Contrast deliberately avoids positive description, but deliberately depicts it from the side, so that the people, things and things to be expressed stand out clearly and receive the artistic effect of "seeing the moon through the clouds" These are two different expressions.