给个英文的.个人理解可能会有点出入.基本上是这个意思. ziUEA>m */
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A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric d:08@~#
units, a luminous intensity plot is in units of candelas (lumens per steradian). In e UMOV ]h
radiometric units, an intensity plot is in units of watts per steradian. Candela plots ;Fw{p{7<
are commonly used in the design of illumination systems, especially those used in c*o05pMS
the far field. ;a@%FWc
Candela data can be collected from ray sets of Missed rays, rays Exiting a surface _P6e%O8C#
or rays Incident on a surface. Missed rays are a collection of all rays that “leave” t[HfaW1W
the model and “go off to infinity.” Exiting rays are the collection of ray segments JC| j*x(k/
following the intersection point of a ray at a surface. Due to ray splitting, several 8nzDLFxp_
ray segments may contribute to the candela data for each incident ray. Incident hSQ*_#
rays are the collection of ray segments which intersect the selected surface. No -'SpSy '_
surface selection is required for Missed rays but one is necessary for Exiting and l ":\@rm`
Incident rays. a2J01B
The candela plots represent flux versus angle and can be smoothed using the 9FB k|g"U)
Candela Options dialog box. The iso-candela plots can be presented as false TmI~P+5w
color maps or contour plots. The distribution plots are graphs of cross-sectional Mr/;$O{
curves through the candela distribution. \0gU)tVZ
The orientation of the candela plots is determined by the Normal Vector and the ~z;G$jd
Up Vector, as specified in the Analysis|Candela Options dialog box. The )fPN6x/e
normal vector specifies the axis of the candela plot and the up vector specifies (^h2 'uB
“which way is up.”
