28 Critical Reflections: random 15 to 21

'Abstract' is a word which is now most frequently used to express only the type of the outer form of a work of art; this makes it difficult to use it in relation to the spiritual vitality or inner life which is the real sculpture. Abstract sculptural qualities are found in good sculpture of all time, but it is significant that contemporary sculpture and painting have become abstract in thought and concept. As the sculptural idea is in itself unfettered and unlimited and can choose its own forms, the vital concept selects the form and substance of its expression quite unconsciously.[7]

This can be explained by the existence of microfacets. We assume that surfaces that are not perfectly smooth are composed of many very tiny facets, each of which is a perfect specular reflector. These microfacets have normals that are distributed about the normal of the approximating smooth surface. The degree to which microfacet normals differ from the smooth surface normal is determined by the roughness of the surface. At points on the object where the smooth normal is close to the half-angle direction, many of the microfacets point in the half-angle direction and so the specular highlight is bright. As one moves away from the center of the highlight, the smooth normal and the half-angle direction get farther apart; the number of microfacets oriented in the half-angle direction falls, and so the intensity of the highlight falls off to zero.[6]

But the first thing to make clear is that a specular reflection cannot be taken as a sign if one follows the definition given in this book. Not only can it not be properly called an image (since it is a virtual image, and therefore not a material expression) but even granted the existence of the image it must be admitted that it does not stand for something else:on the contrary it stands in front of something else, it exists not instead of but because of the presence of that something: when that something disappears the pseudo-image in the mirror disappears too.[3]

So, anyway, the people. Their clothes were shiny too, but lots of different colours. Skin-tight. They wore helmets with stubby aerials, and goggles. But the goggles had lines of information flickering across them.[2]

And the play of inside against/with outside, the seeing through, the laid bare view, makes everything that is around part of the sculpture too.[4]

"Shut up", I told the breakfast table. "I asked for coffee and waffles, not your dream from last night."

I finished my breakfast in a silence that was, I suspect, sulky on one side. "Reflective surfaces, huh? Sometimes they can get above themselves."[2]

The specular highlight often reflects the color of the light source, not the color of the reflecting object. This is because many materials have a thin layer of clear material above the surface of the pigmented material. For example plastic is made up of tiny beads of color suspended in a clear polymer and human skin often has a thin layer of oil or sweat above the pigmented cells. Such materials will show specular highlights in which all parts of the color spectrum are reflected equally. On metallic materials such as gold the color of the specular highlight will reflect the color of the material.[6]

28 Critical Reflections: random 22 to 28
Back to Clive's home page

Sources

[1] http://www.neworleanspast.com/art/id62.html

[2] Ken MacLeod, Reflective Surfaces, New Scientist, 2009.

[3] Umberto Eco, A Theory of Semiotics, Indiana University Press, 1979.

[4] Clive Fencott, Reflections on seeing River Form in Barbra Hepworth's garden in St. Ives.

[5] http://www.flickr.com/photos/nigelhomer/316548379/

[6] http://en.wikipedia.org/wiki/Specular_highlight

[7] http://www.barbarahepworth.org.uk/texts/

[8] tripadvisor.co.uk