给个英文的.个人理解可能会有点出入.基本上是这个意思. E~]8>U?V DYJ@>8 A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric t0p^0 units, a luminous intensity plot is in units of candelas (lumens per steradian). In LX[J6YKR radiometric units, an intensity plot is in units of watts per steradian. Candela plots S P)$K= are commonly used in the design of illumination systems, especially those used in wxEFM)zr the far field. &*RJh'o|N( Candela data can be collected from ray sets of Missed rays, rays Exiting a surface ,/{mRw% or rays Incident on a surface. Missed rays are a collection of all rays that “leave” 2>0[^ .;" the model and “go off to infinity.” Exiting rays are the collection of ray segments g4_DEBh following the intersection point of a ray at a surface. Due to ray splitting, several MjNCn&c ray segments may contribute to the candela data for each incident ray. Incident Ce}wgKzr rays are the collection of ray segments which intersect the selected surface. No Qfr%BQV surface selection is required for Missed rays but one is necessary for Exiting and ~hPp)-A Incident rays. utKtxLX" The candela plots represent flux versus angle and can be smoothed using the $+)2CXQe5 Candela Options dialog box. The iso-candela plots can be presented as false :-7`Lfi@% color maps or contour plots. The distribution plots are graphs of cross-sectional iPX6r4- curves through the candela distribution. l~Je]Qt The orientation of the candela plots is determined by the Normal Vector and the QN:gSS{30 Up Vector, as specified in the Analysis|Candela Options dialog box. The 1tU}}l normal vector specifies the axis of the candela plot and the up vector specifies 'h_PJ% “which way is up.”