给个英文的.个人理解可能会有点出入.基本上是这个意思. ',*
6vbII Z5{M_^ A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric s.I=H^T units, a luminous intensity plot is in units of candelas (lumens per steradian). In #6JCm!s radiometric units, an intensity plot is in units of watts per steradian. Candela plots yHoj:f$$x are commonly used in the design of illumination systems, especially those used in ^Q_0Zq^H the far field. |v{a5|<E Candela data can be collected from ray sets of Missed rays, rays Exiting a surface T3{qn$t8 or rays Incident on a surface. Missed rays are a collection of all rays that “leave” [H)p#x the model and “go off to infinity.” Exiting rays are the collection of ray segments 18!0Hl> following the intersection point of a ray at a surface. Due to ray splitting, several Wcn^IQ ray segments may contribute to the candela data for each incident ray. Incident SR S~s rays are the collection of ray segments which intersect the selected surface. No Z;i^h,j?$1 surface selection is required for Missed rays but one is necessary for Exiting and ;xa]ke3] Incident rays. ^f1}:g The candela plots represent flux versus angle and can be smoothed using the 413r3/ Candela Options dialog box. The iso-candela plots can be presented as false M|`%4vk> color maps or contour plots. The distribution plots are graphs of cross-sectional 5,qfr!hN, curves through the candela distribution. Fk
1M5Dm The orientation of the candela plots is determined by the Normal Vector and the NzRL(A6V Up Vector, as specified in the Analysis|Candela Options dialog box. The s 4}}MV3X normal vector specifies the axis of the candela plot and the up vector specifies H1=R(+-s “which way is up.”