Class 5/6 – May 21st & 22nd 2014 –
After only 4 classes we can now already see major improvements in the quality of your sketches. The wall filled with sketches is starting to look like a wall in a real design studio! The techniques that you are using to communicate the results are really starting to pay off.
We discussed the results and talked about the rules of linear perspective again and how they influence the proportions of a product. I was glad to see that more and more of your results appear to be part of an exploration (blue sketches being visible).
Today’s class is about cylindrical objects and perspective. In order to draw cylinders it is crucial to practice drawing circles and ellipses until they become fluent. The best way to do this is by drawing from the shoulder while pointing your pen (or pencil) perpendicular to the major axis of the ellipse. Avoid using finger or wrist motion while drawing for these will create unbalanced non-symmetrical ellipses.
We looked at a 3D model of a cylinder and analyzed the behavior of the lines and ellipses in perspective. Just like with the cubes it really helps to understand this behavior first before trying to reproduce it yourself.
The main principle of a cylinder in perspective is that the major axis is always positioned perpendicular to the axis of rotation (center line). Furthermore the ellipse that is the closest to the viewer (or the horizon) will be the narrowest. The longer the distance to the viewer the rounder the ellipse.
Another important realization is the fact that the ellipses do not follow the direction of the rectangular surface that they sit on. You can rotate the surface as much as you want, but the cylinder remains unchanged.
We sketched a simple block and cut it with cylindrical holes from all sides. Most of you ran into trouble immediately. It is tempting to align your ellipse with the orientation of the surface it sits on, but as we’ve seen before, the direction of the ellipse (angle of major axis) is unrelated to that surface. Instead it should ALWAYS be placed perpendicular to the axis of rotation of the cylinder, which in turn is pointing at one of the vanishing points. The only thing you have to estimate is the ratio of the ellipse: the length of the minor axis in relation to the major axis (the roundness of the ellipse). You can relate the roundness to the foreshortening of the surface that the ellipse sits on. To check your ellipse you could draw a square onto the surface and see if the ellipse fits inside.
Then we’ve looked at images of products and analyzed their geometry and the ellipses in particular. We located the axis of rotation, the minor and major axis and the vanishing points and copied the objects in a series of sketches. I demonstrated how to apply marker to a cylinder to make it appear 3D using a core shadow and a highlight. In general the following principles apply: on a matte surface the values will blend into a smooth gradient and on a glossy surface the different values (reflections) will be quite sharp and have lots of contrast.
To do for next class:
Produce an exploration (!) of camera’s in perspective with the photo reference material and (optionally) other cylindrical objects. Just like last weeks exercise you should also practice rotating the objects mentally and sketch them in different perspectives. Don’t forget to do some warm-up ellipses and circles before you start! Finally take some time to communicate a couple of the results applying black felt-tip and grey markers. Add a layer of communication to the whole page explaining what can be seen on the page.