man with hands on hips
An oblique drawing is a simple form of three-dimensional (3D) drawing that is usually created for drafting or engineering. This drawing usually consists of an object where the front of the object is drawn flat, with the height and width of the object drawn at the appropriate lengths. The object is given depth through sides drawn at an angle to create the feeling that the object is three-dimensional; this is usually at a 45° angle and the sides can be shortened. An oblique design is typically one of three types: normal, cabinet, or gentlemanly.
To create an oblique drawing, an engineer or designer often starts with a “three view drawing”. It consists of a single object represented in three different views: front, side and top. The front drawing is usually created first to establish the height and width of the object. The vertical lines of the front view can be extended up the paper, the depth of the object is added to them and this creates the top view. The horizontal lines of the front view can be extended to the side of the front view, the proper depth is again used and the side view is created.
With a three-view drawing, a designer or engineer can easily create an oblique drawing. This is done by using the height and width of the front view and keeping them the same size. The depth of the top and side views can be used to add depth to the oblique drawing and create a 3D feel to the image. While any angle can be chosen to create the depth lines, a 45° angle is often chosen because of the easily visible nature of the lines at that angle.
The length of the lines used to add depth to the object determines the type of oblique design that is created. Normal oblique drawings use depth lines that are only three-fourths the length of the depth set by the three-view drawing. Cabinet designs use lines that are only half the length of the original depth lines to create the oblique object.
In any of these types, the object will appear shortened and will look closer to how it might actually appear in 3D space. A chivalrous oblique drawing, on the other hand, uses depth lines that are the same length as the top and side views in the three-view drawing. While this preserves the sizes given in the three-view image, the perspective created by this type of oblique is much more exaggerated.