MODELLING

Modelling of a shape derives from its physical form, whether round,
square or otherwise, coupled with the way in which light plays on its
surfaces. This is referred to as its modelling and when this derives from
daylight or sunlight, giving light from a single direction, this provides a
form which is perceived by the eye as having meaning, unambiguous.
This is a different experience again from the form of an object or space
resulting from a room lit by artificial light, where the overall light may be
received from a multitude of light sources.
The most usual daylight modelling is that derived from vertical
windows at the side of a room, giving light from a single direction; this
may be helped by windows from an adjacent wall which adds to the
modelling; as the light will still be from the same overall direction, but
adding to the total modelling.
Two examples might be used to emphasize this, the first, a Greek Doric
column where the light of day gives modelling to the entasis on the
rounded surfaces of the column; light which emphasizes its particular
rounded quality together with its verticality. The second example is the
original David statue by Michelangelo seen in its setting in the art gallery
in Florence, lit from daylight above, where the form changes in time as
the day goes by.

A more modern example of the use of overhead daylight to light a
statue is the Charioteer in Delphi (Case Study pp. 170–171).
Daylight by its nature gives meaning and aids our understanding of a
shape or space by its directional flow; a meaning which is emphasized
even further by the addition of direct sunlight.
Interior spaces are judged to be pleasant, bright or gloomy as a result of
the effects of modelling and interiors are judged by the way in which the
spaces and the objects within them are seen during the day to be natural,
or accord to our experience of the natural world.