给个英文的.个人理解可能会有点出入.基本上是这个意思. %+ZJhHT
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A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric ^\B :R,
units, a luminous intensity plot is in units of candelas (lumens per steradian). In P mi#TW3X
radiometric units, an intensity plot is in units of watts per steradian. Candela plots %p&k5:4<"#
are commonly used in the design of illumination systems, especially those used in ]nhr+;of/-
the far field. KYJjwXT28W
Candela data can be collected from ray sets of Missed rays, rays Exiting a surface :b[`
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or rays Incident on a surface. Missed rays are a collection of all rays that “leave” bVmA tm[
the model and “go off to infinity.” Exiting rays are the collection of ray segments XPB9~::
following the intersection point of a ray at a surface. Due to ray splitting, several oJKa"H-jL
ray segments may contribute to the candela data for each incident ray. Incident ;U t+yuy
rays are the collection of ray segments which intersect the selected surface. No P,ua<B}L
surface selection is required for Missed rays but one is necessary for Exiting and ]]}tdn _
Incident rays. g<*BLF
The candela plots represent flux versus angle and can be smoothed using the 6 \B0^
Candela Options dialog box. The iso-candela plots can be presented as false g~UUP4<$"
color maps or contour plots. The distribution plots are graphs of cross-sectional 8 i&_Jgmr
curves through the candela distribution. RvJ[ '(-
The orientation of the candela plots is determined by the Normal Vector and the m8623D B"
Up Vector, as specified in the Analysis|Candela Options dialog box. The >h Y"
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normal vector specifies the axis of the candela plot and the up vector specifies .k TG[)F0b
“which way is up.”
