给个英文的.个人理解可能会有点出入.基本上是这个意思. TH+TcYqO hxGo~<. : A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric h5[.G! units, a luminous intensity plot is in units of candelas (lumens per steradian). In = Ruq radiometric units, an intensity plot is in units of watts per steradian. Candela plots -i4hJC!3 are commonly used in the design of illumination systems, especially those used in ~P9^4 the far field. &9xcP.3 Candela data can be collected from ray sets of Missed rays, rays Exiting a surface 7[8d-Sf24{ or rays Incident on a surface. Missed rays are a collection of all rays that “leave” &lW~ot1, the model and “go off to infinity.” Exiting rays are the collection of ray segments ;5}"2hU> following the intersection point of a ray at a surface. Due to ray splitting, several dV"Kx ray segments may contribute to the candela data for each incident ray. Incident {;hRFQ^b rays are the collection of ray segments which intersect the selected surface. No K Z0%J5 surface selection is required for Missed rays but one is necessary for Exiting and 5ma~Pjt8} Incident rays. j g_;pn The candela plots represent flux versus angle and can be smoothed using the dj3E20Ws Candela Options dialog box. The iso-candela plots can be presented as false q_:B=w+bC color maps or contour plots. The distribution plots are graphs of cross-sectional wE_#b\$=b curves through the candela distribution. 9>d~g!u= The orientation of the candela plots is determined by the Normal Vector and the ;*e$k7}F Up Vector, as specified in the Analysis|Candela Options dialog box. The hle@= e/n normal vector specifies the axis of the candela plot and the up vector specifies _u;34H&/ “which way is up.”