给个英文的.个人理解可能会有点出入.基本上是这个意思. nu {bEp
WH F>J
A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric -lM4 *+f
units, a luminous intensity plot is in units of candelas (lumens per steradian). In 8U8l
5r
radiometric units, an intensity plot is in units of watts per steradian. Candela plots 7xAzd#
c?=
are commonly used in the design of illumination systems, especially those used in gn&jNuGg
the far field. tcY bM+4e
Candela data can be collected from ray sets of Missed rays, rays Exiting a surface wv>uT{g#
or rays Incident on a surface. Missed rays are a collection of all rays that “leave” r2A(GUz
the model and “go off to infinity.” Exiting rays are the collection of ray segments 3%Jg' Tr+
following the intersection point of a ray at a surface. Due to ray splitting, several [4:_6vd7X
ray segments may contribute to the candela data for each incident ray. Incident \BC|`)0h
rays are the collection of ray segments which intersect the selected surface. No k'u N2 m
surface selection is required for Missed rays but one is necessary for Exiting and )Yvf9d l
Incident rays. _@3?yv~ D
The candela plots represent flux versus angle and can be smoothed using the ,^ M A,"8
Candela Options dialog box. The iso-candela plots can be presented as false ^E&':6(
color maps or contour plots. The distribution plots are graphs of cross-sectional ShAI6j
curves through the candela distribution. eR.ucTji
The orientation of the candela plots is determined by the Normal Vector and the yZ t}Jnv
Up Vector, as specified in the Analysis|Candela Options dialog box. The 0 r=:l/Pz
normal vector specifies the axis of the candela plot and the up vector specifies rf"%D<bb
“which way is up.”
