Three dimensional front projection Horizontal projection And side projection are respectively referred to as Home View , top view, and left view. These three views are the most important for us to show the structure of objects“ Three view ”。 Left view means that the viewpoint is on the left side of the object and projected on the right side of the object. In short: the left view is to look from the left to the right of the main view and draw it on the right side of the main view (this is the Chinese standard). The front view reflects the up and down and left and right position relationship of the solid;
The top view reflects the relationship between the front, rear, left and right positions of the solid;
The left view reflects the relationship between the front, rear, top and bottom positions of the stereo.
Only one projection cannot uniquely determine the space shape. Two different shapes in space may have the same projection on a plane. In order to completely determine the shape of the figure, the figure can be projected onto two or more projection planes that are perpendicular to each other, and then the projection plane and the projection on it can be spread and flattened onto the same plane Orthographic projection be called Polyhedral orthographic drawing 。 The three orthogonal projections of the body are made on three mutually perpendicular projection planes, and the shape and size of the body can be uniquely determined by the three projections. Multiface orthographic projection can reflect the actual shape and size of the body, with good measurement and simple drawing. It is widely used in engineering, but its disadvantage is poor intuition.
Drawing software involves a lot, such as cad 、 ug Wait, ordinary beginners are easy to confuse the left view with the Right view In this simple legend, the left view means that the viewpoint is on the left side of the object and projected on the right side of the object; The right view is the opposite. [1] 
