|
|
 |
 |
 | | | | |
 |
|||
 |
||||||
          |
 |
 |
||||
|
Conceptual Design: Understanding and Communicating Form Seeing Organic FormOne of the principles that designers have observed over the years is that we don't really see form, what we see is the way in which form manipulates light before it is reflected back into our eyes. This may seem like an esoteric piece of semantics, but embracing it is fundamental to understanding how to manipulate the graphic nature of three-dimensional form. This means how to properly illustrate it, yes, but also how to truly design it with control over how it will appear from various angles and in different lighting. Designing surface is really about designing highlights and reflections. Shiny or metallic surfaces reflect differently as you observe them from different angles. It is the movement of reflections and highlights across those surfaces that describes to our eye the forms they are enveloping. What's more, subtleties of surface curvature can drastically affect how and where a reflection or highlight falls, as well as the speed at which it crosses a given area of surface when either our eye, or the object, or whatever is being reflected is moving. This significantly alters our perception of the underlying shape. Differences in surface properties also affect our perception of form, as does color. Metallic surfaces will gather diffuse highlights anywhere where a surface is 'bending' or changing direction, lending graphic strength to the intersections of surfaces. As well, they tend to get 'toned' by the colors around them, allowing contrasts of warm and cool colors to indicate the direction of surfaces. Glossy materials will pick up distinct reflections which can delineate the cross-section of a form through the way they fall and the degree to which they are distorted by the surface. All of these are thankfully governed by observable physical principles which, when understood, can be applied to our rendering. Understanding how surface manipulates light can begin by observing the simple cylinder. By simplifying to an object with curvature in a single direction, one can isolate the different effects of horizontal and vertical curvature, and then extrapolate the results on any compound surface with a greater degree of understanding. Let's start out by looking at the physics of it. Light reflects off of a flat surface at an angle exactly opposite to the angle it came in at. Seen another way, it is "mirrored" across the axis of a line perpendicular to the surface, otherwise known as the surface normal. To figure out where a reflection will fall on this surface, you mentally trace the path between the source of the reflection and the "eye", ensuring that the path passes through the proper angle of reflection on the surface. That point is where the reflection will be seen on the surface. The same is true of highlights, tracing the path from the light source, through reflection, to the eye.
Tracing reflections on a curved surface is simply a matter of finding the perpendicular to that surface at any given point, in other words, the surface normal. Just think of a curved surface as an infinite number of flat mirrors linked along a curve (like a disco ball). For all intents and purposes, the surface at that infinitesimal point where a ray of light hits can be considered 'flat' and the process is the same.
The way in which I try to plot reflections is to find the most contrasting edge in whatever is being reflected, as this will end up being the strongest graphic element on the surface. Then I figure out where this will land across my surface. For the purposes of illustrating the form a 'horizon line' is ideal. It provides a clear delineation between elements reflecting above and below eye level, and generally provides warm ground tones and cool sky tones to further emphasize the changes in curvature. Basically, it makes very clear what part of the surface is facing 'down' and what part is facing 'up'.
A good tool for observation is a flexible sheet of glossy or reflective material, such as Mylar. You can also spray a sheet of glossy paper or thin plastic with silver spray paint. If you spray a sheet of transparent plastic, such as acetate with silver paint, you will have created a flexible mirror for observing reflections on one side, and a silver sheet for reflecting highlights on the other. By bending your mirror in various directions, you can observe how it is distorting the world around you. Ideally, you should find an environment that has a distinct horizon, 'sky' and 'ground' to simplify your observation. Try going outside. If you roll the sheet into a horizontal cylinder, you can see that the reflections are compressed vertically, and begin to appear long and thin. Roll the sheet into your hand to form a hollow half-cylinder. The reflections have compressed in the same manner, but now reversed, with the 'sky' reflected in the lower half, and the 'ground' in the upper.
Now turn your original cylinder vertically. You will notice that any roughly horizontal line below your eye level in the environment will appear to 'climb' or bend upward in its reflection as it goes away from you, and hence toward the vanishing point on the horizon. The opposite is true of lines above your eye level. As well, any subtle variations in the height of what is being reflected around you become drastically exaggerated as they are compressed by the curvature of your cylinder. These simple observations are the foundation of understanding how complex rounded surfaces distort reflections, and, more importantly, how form can be described by the application of these phenomena to your drawing. Now take
out your 'diffuse' sheet, and bend it into a positive horizontal half-cylinder.
Rather than making it perfectly cylindrical, however, pinch it more toward
the center so that it forms more of a loose bend through the middle, like
a 'v' section on it's side with a rounded point.
Keeping
the "pinch" at one end, let your sheet unroll into more of a
regular cylinder at the other end. Notice how the highlight 'flares' out
and diffuses as the curvature of the bone lessens. You have just created
a 'coning' bone in your surface. Coning is also a very powerful tool in
surface development, and can be thought of as the three-dimensional equivalent
of varying your line weights in a drawing. ______________________________________________________ |
||||||||||||||||||||||||||||||||||||||||||||
|
|
Features
