PLAN

     PLAN is looking at the building from above. It is an orthographic projection of a 3-dimensional object from the position of a horizontal plane through the object. It can show the general layout of the building, for example how the walls lay on different floors, the arrangement of furniture, the relationship between the building and the surrounding.

     Every time we design a room or building, we usually draw a plan first. For drawing a plan, lines are important. For example, we should draw the line once, do not copy many time. When drawing a curved line, it should be smooth.

ELEVATION

     ELEVATION describes the outer appearance of a building. It is a view of a 3-dimensional object from the position of a horizontal plane beside an object. In other words, an elevation is a side-view as viewed from the front, back, left or right. With a series of elevation, we can know the complete outlook of the architecture.

     Elevation is a common method of depicting the external configuration and detailing of a 3-dimensional object in two dimensions. Building façades are shown as elevations in architectural drawings and technical drawings.

     It also is the most common orthographic projection for conveying the appearance of a building from the exterior.  A building elevation is typically labeled in relation to the compass direction it faces; the direction from which a person views it. E.g. the North Elevation of a building is the side that most closely faces true north on the compass.

PERSPECTIVE

     PERSPECTIVE is one kind of drawings in 3D expression. It is drawn like what you can see in reality, or to simulate the possible view at a certain viewpoint.

     There are many types of perspective drawings, the most common categorizations of artificial perspective are one, two and three-point. The names of these categories refer to the number of vanishing points in the perspective drawing.

ONE-POINT PERSPECTIVE

One vanishing point is typically used for roads, railway tracks, buildings viewed etc. As a result, the front is directly facing the viewer. Any objects that are made up of lines either directly parallel with the viewer's line of sight or directly perpendicular (the railroad slats) can be represented with one-point perspective.

TWO-POINT PERSPECTIVE

Two-point perspective can be used to draw the same objects as one-point perspective, rotated: looking at the corner of a house, or looking at two forked roads shrink into the distance, for example. One point represents one set of parallel lines, the other point represents the other. Looking at a house from the corner, one wall would recede towards one vanishing point, the other wall would recede towards the opposite vanishing point.