2012

 Flux (Lumen). Represents the rate of total energy leaving the lamp. It is
specified in lumens (SI and American). Mathematically, the flux is the
integral of the luminous intensity over the sphere. The calculation of flux
depends on the distribution of intensities. For a point light with constant
intensity, the flux is simply the product of the intensity and the solid angle
of a sphere: 4 Pi * Intensity. For a spot light, the flux is the product of the
intensity and the solid angle of the hotspot cone, plus the incremental
solid angle of the fall-off region. For a weblight, there isn’t any analytical
formula. The flux is obtained by numerically integrating the intensities
provided in the web file.
 Illuminance (Foot-candles). Represents the energy per area arriving at
a surface (Area-flux-density). It is specified in lux (SI) and foot-candles
(American). For a near light, because the light rays are diverging, you have
to talk about the illuminance at a specific distance from the lamp. So this
requires an extra control to specify this distance and an additional
affordance in the viewport to show the distance.
Lamp Intensity Specifies the brightness of a lamp. More specifically, it
represents the luminous intensity, or power in a particular direction.
Intensity Factor Magnifies the effect of the skylight.
Resulting Intensity Reports the final brightness of the light. This is determined
by the product of the Lamp Intensity and the Intensity factor. (Read-only)
PhotometricWeb
The following property settings are available for Web and Freeweb lights:
Web File Specifies the data file describing the intensity distribution of the
light.
Web Offsets
Under the Web offsets panel, the following property settings are available
under the Weblight and Freeweb types of lights:
Rotate X Specifies a rotational offset of the web about the optical X axis.
Rotate Y Specifies a rotational offset of the web about the optical Y axis.
Rotate Z Specifies a rotational offset of the web about the optical Z axis.
Geometry
Under the Geometry panel, the following property settings are available:
Position X Specifies the X coordinate position of the light.
Position Y Specifies the Y coordinate position of the light.
Commands | 839