What is the law of three-view projection?

The length of the front view and the top view should be equal.

The height of the main view and the left view should be equal.

The width of the left view and the top view should be equal.

In many cases, it is impossible to express and determine the shape and structure of the body completely and clearly with only one projection without any comments. As shown in the figure, the projection of the three bodies in the same direction is exactly the same, but the spatial structure of the three bodies is different.

It can be seen that it is impossible to express the shape of an object only by projection in one direction. Generally speaking, the shape and structure of the body must be projected in several directions in order to be fully and clearly expressed.

Extended data:

A person's line of sight is defined as a parallel projection line, and then he looks directly at the object. The figure drawn by the orthogonal projection method is called a view. An object has six views:

The view projected from the front to the back of an object is called the front view (front view)-it can reflect the front shape of the object, and the view projected from the top to the bottom is called the top view-it can reflect the upper shape of the object, and the view projected from left to right is called the left view (side view)-it can reflect the left shape of the object, and there are three other less commonly used views. Three views are the front view (front view), top view and left view (side view).

Baidu encyclopedia-three views