给个英文的.个人理解可能会有点出入.基本上是这个意思. vX!dMJa0 dk,
I?c& A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric _mq*j^u,j units, a luminous intensity plot is in units of candelas (lumens per steradian). In 2*UE&Gp radiometric units, an intensity plot is in units of watts per steradian. Candela plots 71.:p,Z@z are commonly used in the design of illumination systems, especially those used in S'H0nJ3 the far field. :pV("tHE Candela data can be collected from ray sets of Missed rays, rays Exiting a surface .\hib.n3 or rays Incident on a surface. Missed rays are a collection of all rays that “leave” .w*{=x0k the model and “go off to infinity.” Exiting rays are the collection of ray segments :[ZC-hc\ following the intersection point of a ray at a surface. Due to ray splitting, several [F9KC^%S ray segments may contribute to the candela data for each incident ray. Incident =6 q*w^ET rays are the collection of ray segments which intersect the selected surface. No K:Xrfn{s surface selection is required for Missed rays but one is necessary for Exiting and v"?PhO/{= Incident rays. He$mu=$q{ The candela plots represent flux versus angle and can be smoothed using the O( sFs1 Candela Options dialog box. The iso-candela plots can be presented as false [laL6 color maps or contour plots. The distribution plots are graphs of cross-sectional ezNE9g curves through the candela distribution. 8b#Yd
The orientation of the candela plots is determined by the Normal Vector and the 86)
3XE[5 Up Vector, as specified in the Analysis|Candela Options dialog box. The t+TbCe normal vector specifies the axis of the candela plot and the up vector specifies 2w.9Q
(Sn “which way is up.”