给个英文的.个人理解可能会有点出入.基本上是这个意思. HK!ecQ^+ B'}?cG] A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric W*C~Xba< units, a luminous intensity plot is in units of candelas (lumens per steradian). In "Q.* radiometric units, an intensity plot is in units of watts per steradian. Candela plots Ym6d'd<9( are commonly used in the design of illumination systems, especially those used in `t U the far field. SB\%"nnV Candela data can be collected from ray sets of Missed rays, rays Exiting a surface D`LBv,n or rays Incident on a surface. Missed rays are a collection of all rays that “leave” P"vrYom the model and “go off to infinity.” Exiting rays are the collection of ray segments n[ B~C following the intersection point of a ray at a surface. Due to ray splitting, several B ?VTIq> ray segments may contribute to the candela data for each incident ray. Incident 6z 9
'|;,4 rays are the collection of ray segments which intersect the selected surface. No P"w\hF surface selection is required for Missed rays but one is necessary for Exiting and \]9)%3I Incident rays. >pU9}2fpT The candela plots represent flux versus angle and can be smoothed using the E8#
>k Candela Options dialog box. The iso-candela plots can be presented as false _M^.4H2 color maps or contour plots. The distribution plots are graphs of cross-sectional rpT.n-H>%A curves through the candela distribution. &N7ji The orientation of the candela plots is determined by the Normal Vector and the X$Vi=f vt Up Vector, as specified in the Analysis|Candela Options dialog box. The 8 t5kou]h normal vector specifies the axis of the candela plot and the up vector specifies "}]$ag!`q$ “which way is up.”