An isometric drawing is a three-dimensional representation of an object on a two-dimensional surface. Three views of the same image are combined to make an isometric drawing. The blueprint drawing can be accomplished freehand or by using computer drafting computer software. This type of technical drawing is commonly used in engineering, architecture and related fields.
When engineers and architects try to illustrate an object, they draw the object as seen from different sides. These views include the top, bottom, front, back, left side and right side. Placing all the different views in a single blueprint is known a multi-view drawing. Multi-view illustrations are two-dimensional. This type of drawing helps translate those images to create a three-dimensional object.
For people who have no background in engineering or architectural, a multi-view drawing can be difficult to understand. The problem with a multi-view is the individual reader has to be able to decipher what the different types of lines mean and put the different views together to form an image. Translating a multi-view drawing requires skill and imagination to mentally round out how the image looks. This is where an isometric drawing becomes beneficial. It combines three adjacent views to create an image with depth and volume.
Isometric drawings are only one of several types of pictorial drawings used to illustrate objects in three-dimensional forms. Perspectives and isometric projections are other ways of translating a multi-view drawing. Each type has a different look and purpose.
This type of drawing is different from a perspective in that perspectives are used to give a feeling of distance. Objects that are farther away appear smaller than those closer, even if both objects are the same size. In these drawings, the lines remain parallel whether an edge is nearer or farther away. With perspective drawings, parallel lines move closer to one another until they converge at the vanishing point.
Equally confusing is the term isometric projection. Both the isometric drawing and the isometric projection are types of axonometric projections, but they produce slightly different results. The difference is in how the two sides are drawn.
In an isometric drawing, the angle between the two base edges is 90°. When doing an isometric projection, a base line is drawn. The two connecting base edges are drawn measuring 30&deeg; from the base line, creating a 120° angle between the two edges. As a result, an isometric projection is smaller. The size of the object drawn using an isometric projection is only 80 percent of that of an isometric drawing.
