What is bicontinuous and tetragonal continuous pattern?

Bidirectional continuity is a pattern formed by repeating a single pattern (one pattern or two or three patterns combined into a unit pattern) up and down or left and right. There are three continuous bone methods: vertical bone, scattered bone and corrugated bone.

Quadrilateral continuity is a pattern form composed of one pattern or several patterns, which is repeated and continuous in four directions: up, down, left and right.

There are two common methods for continuous arrangement of squares: parallel arrangement and trapezoidal arrangement.