Those of you new to Autocad will often ask the main difference between the 2D and 3D functionality of the program. It was first released in 1982 as an MS-DOS application, and since then has developed into the large, complex program we know today, becoming the world-leader in CAD, or computer aided design, programs. As such Autocad initially created only 2D drafting drawings, but in 1992 AutoDesk introduced its brand-new 3D modeling engine. And in the last few releases this has become increasingly complex and powerful. Both sets of functions exist within Autocad but there are two separate workspaces for 2D drawings and 3D modeling, but it’s very easy to switch between them.
Both Autocad 2d and 3d are used by a variety of professions, architecture and construction being the main ones, as well as engineering, interior and landscape design. The high points of the 2D functions are their ability to draw and modify geometry accurately, together with adding precise dimensions and annotations. This geometry can be viewed at different scales in Paper Space and organized using various industry-specific layers, line-types and colours. A variety of sheet layouts for printing are often set up within a company’s template file, with several symbols or blocks being imported for multiple objects within the drawing.
In contrast the main features of the 3D workspace are the creation and modification of solid objects within 3D space. These may be extruded from the 2D drawing or created from scratch using the various solid modeling tools. We can then apply real-world materials and lighting to the model in order to created photo-realistic images. Cameras may also be added to output the scene as an animated movie.
In earlier versions of the program 3D views of an object were created using isometric views. Over the last ten years or so these have largely been superseded due to the 3D functionality of Autocad. However, we may still need to draw a simple isometric drawing for a construction to give a client a simple idea of how the object looks in three dimensions. Such drawings can also be used for piping diagrams.
To help with the drawing it’s often a good idea to snap to an isometric grid. To set the grid up first right-click on the Snap icon on the bottom Status bar to click on Settings. We then select Isometric Grid and give the Snap and Grid a certain spacing factor. On the Status bar also turn on Grid (or hit the keyboard shortcut of F7) and Snap (F9).
Select the Line or Poly-line tool and create an upright line. As you do so the tool will want to snap to the grid lines. We can also draw lines at thirty or forty-five degree angles, thus giving us our isometric view of the object. Note that in such drawings there is no perspective fore-shortening; lines are always their measured values. We can then use the Move, Copy, Rotate and Mirror tools as usual to modify our drawing.
When we have completed the isometric part of the drawing we can return to the normal snapping function by typing Snap into the Command line, S for Style and S for Standard. Or simply turn off the Snap and Grid visibility.
This is a simple alternative to working in the 3D space of Autocad, and the only real option if you have the Autocad LT (or Lite) version, which does not include 3D functionality.
Tom Gillan has been training Indesign to corporate clients in Sydney for seven years. You can learn more about AutoCAD 2D at http://www.designworkshopsydney.com.au/autocad-2d-courses/ .