2D and 3D
A freehand drawing or sketch is a quickly executed drawing that is not intended as a finished work. In general, sketching is a quick way to record an idea for later use and is often completed during early consultations with clients.
It is also a technique used by an Architect or designer to try different ideas and establish a composition before undertaking a more finished work, especially when the finished work is expensive and time consuming. The ability to produce an accurate drawing in freehand is vital for the a successful completion of a design project. Most original ideas begin as a freehand sketch. Engineers usually prepare their designs in sketch form and then hand them over to CAD specialist to complete detailed scale drawings. Drawings documenting changes in design or the replacement of broken parts are completed through freehand sketching often onsite and without the convenience of drawing equipment.
The level of perfection needed in a given sketch depends on its ultimate use. Sketches that are hurriedly made to supplement an oral description may be rough and incomplete. On the other hand, if the sketch conveys important and precise information to people it should be made as carefully as possible under the circumstances.
Freehand sketches should be used in the development of ideas when documenting the design and management of your major project.
A 2D drawing is flat. The image has only two dimensions and if turned to the side becomes a line. An orthogonal drawing is an example of a 2D drawing. A 3D drawing adds a 3rd dimension. This third dimension allows for rotation and depth. It is essentially the difference between a painting and a sculpture. Some examles of 3D drawings are Isometric drawings, Oblique drawings and Axometric drawings.
3D Isometric cube