给个英文的.个人理解可能会有点出入.基本上是这个意思. BT^=p 'PW/0k A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric 4PR&67|AH_ units, a luminous intensity plot is in units of candelas (lumens per steradian). In w@YPG{"j radiometric units, an intensity plot is in units of watts per steradian. Candela plots "4T36b are commonly used in the design of illumination systems, especially those used in N6T the far field. `K[r5;QFKf Candela data can be collected from ray sets of Missed rays, rays Exiting a surface |mdf u= or rays Incident on a surface. Missed rays are a collection of all rays that “leave” |5q,%9_ the model and “go off to infinity.” Exiting rays are the collection of ray segments /qq*"R following the intersection point of a ray at a surface. Due to ray splitting, several %U.x9UL ray segments may contribute to the candela data for each incident ray. Incident vXSA_"0t rays are the collection of ray segments which intersect the selected surface. No KV'3\`v@LY surface selection is required for Missed rays but one is necessary for Exiting and &uV|Ie8@q Incident rays. o4j!:CI The candela plots represent flux versus angle and can be smoothed using the : Q2=t! Candela Options dialog box. The iso-candela plots can be presented as false ae2I,Qt% color maps or contour plots. The distribution plots are graphs of cross-sectional 9Uz2j$p7 curves through the candela distribution. aW;)-0+ The orientation of the candela plots is determined by the Normal Vector and the 9KT85t1# Up Vector, as specified in the Analysis|Candela Options dialog box. The {}gL*2:EW$ normal vector specifies the axis of the candela plot and the up vector specifies vfVF^
WOd “which way is up.”