Difference between Perspective, Isometric, Oblique and Orthographic Drawing

Perspective Drawings:

If you look along a straight road, the parallel sides of the road seem to meet at a point in the distance. This point is called the vanishing point. To draw in perspective, draw a horizontal line and continue to dot a point as the vanishing point.Straight lines are to be drawn from the vanishing point to the sides of the paper as guide lines. Objects in a perspective drawing are drawn smaller as their distance from the observer increases. As their distance from the observer decreases they are drawn larger.

References:

http://en.wikipedia.org/wiki/Perspective_(graphical)

http://mathforum.org/sum95/math_and/perspective/perspect.html

Drawing taken from:

jhh.blogs.com/anthos/ 2006/01/add_windows_to_.html

Isometric Drawings

Isometric Drawings are all 3D drawings. Only 3 sides of the object drawn is shown. Drawing in Isometric requires us

to draw all the vertical lines vertically but all horizontal lines at 30 degree to the base line.

References:http://toolboxes.flexiblelearning.net.au/demosites/series9/905/2_draw/draw_t3/htm/draw3_2_2.htm

Drawing taken from:

library.thinkquest.org/ TQ0310106/iso.html

Oblique Drawings

Oblique Drawings are also in the 3D format. But how is it different from isometric drawings? The objects in a oblique drawing is drawn with the most distinguishing features facing directly towards the observer, showing the true shape of these features. Circular features like round holes can be drawn on this front face as true circles. In other 3D forms like isometric drawings, circular features must be drawn as ellipses.

References:

http://toolboxes.flexiblelearning.net.au/demosites/series9/905/2_draw/draw_t3/htm/draw3_2_2.htm

Drawing taken from:

library.thinkquest.org/ TQ0310106/oblique.html

Orthographic Drawings

When drawing orthographic drawings, the observer present a 3D image in two dimensions.

When producing an orthographic drawing you will generally produce three views. A plan view,end elevation and a front elevation. The plan view is the view of objects when we look directing down on the top of the objects End elevation is either or sometimes both the remaining side views. Last but not least, front elevation is the view when we look straight on the front of the objects.

References: http://www.design-technology.org/lesson2.htm

Drawing taken from: www.hollyzell.com/ art121a.htm