343
line, or spot lighting sources are available for use in illuminating
environments.
Designers now have available to them a number of computer-based tools with which they can make lighting simulations
and predict lighting levels and characteristics at different points
within a space. These light characteristics can be quantitatively
determined. Fully rendered images are useful for visualization
purposes. Inputs to simulation packages normally include geometric data describing the environment, photometric data to
describe light sources and further geometric data to describe their
locations and configurations, and material property data (reflection, absorption, transmission, or refraction characteristics). Two
general simulation approaches are commonly used: radiosity and
ray tracing. Radiosity methods generally start with the propagation of diffuse light from light sources (defined as surfaces
that self-emit light). Surfaces are subdivided into patches with
specified reflectivities (determined from material considerations).
Despite the power of existing simulation methods, designers are
well advised to understand their limitations thoroughly. As previously noted, many highly subjective aspects of working with light
are simply not possible to consider in any mathematically based
simulation model. Nonetheless, simulation methods remain powerful tools if used correctly. It is also in the self-interest of developers of nanomaterials intended for this application domain to
look into them carefully and understand how materials and lightemitting sources are modeled and provide the necessary property
measures and data to support the modeling. This would promote
their product use.
In closing this section, a further word about lighting standards for
various kinds of spaces (such as classrooms or corridors) should
be noted. Standards or recommendations for appropriate levels
are necessary and can be useful, but they should always be critically viewed in working with lighting, given its many subtle aspects.
Many designers argue, for example, that our environments are
simply “overlighted” by virtue of having to conform to existing
standards, especially since many have their historical roots in the
lighting industry, which accrued benefits from the use of high lighting levels. Many tasks do indeed require high light levels, but it
is easy to overdo light levels as well, to the extent that the excess
light is counterproductive to either comfort or task performance.
High light levels are also complicit in contributing the world’s enormous use of energy, particularly in highly industrialized countries.
In general, more detailed and thoughtful simulation analyses that
Light and Optical Environments
line, or spot lighting sources are available for use in illuminating
environments.
Designers now have available to them a number of computer-based tools with which they can make lighting simulations
and predict lighting levels and characteristics at different points
within a space. These light characteristics can be quantitatively
determined. Fully rendered images are useful for visualization
purposes. Inputs to simulation packages normally include geometric data describing the environment, photometric data to
describe light sources and further geometric data to describe their
locations and configurations, and material property data (reflection, absorption, transmission, or refraction characteristics). Two
general simulation approaches are commonly used: radiosity and
ray tracing. Radiosity methods generally start with the propagation of diffuse light from light sources (defined as surfaces
that self-emit light). Surfaces are subdivided into patches with
specified reflectivities (determined from material considerations).
Despite the power of existing simulation methods, designers are
well advised to understand their limitations thoroughly. As previously noted, many highly subjective aspects of working with light
are simply not possible to consider in any mathematically based
simulation model. Nonetheless, simulation methods remain powerful tools if used correctly. It is also in the self-interest of developers of nanomaterials intended for this application domain to
look into them carefully and understand how materials and lightemitting sources are modeled and provide the necessary property
measures and data to support the modeling. This would promote
their product use.
In closing this section, a further word about lighting standards for
various kinds of spaces (such as classrooms or corridors) should
be noted. Standards or recommendations for appropriate levels
are necessary and can be useful, but they should always be critically viewed in working with lighting, given its many subtle aspects.
Many designers argue, for example, that our environments are
simply “overlighted” by virtue of having to conform to existing
standards, especially since many have their historical roots in the
lighting industry, which accrued benefits from the use of high lighting levels. Many tasks do indeed require high light levels, but it
is easy to overdo light levels as well, to the extent that the excess
light is counterproductive to either comfort or task performance.
High light levels are also complicit in contributing the world’s enormous use of energy, particularly in highly industrialized countries.
In general, more detailed and thoughtful simulation analyses that
Light and Optical Environments