给个英文的.个人理解可能会有点出入.基本上是这个意思. ~m56t5+uw /TgG^|
A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric !>+Na~eN units, a luminous intensity plot is in units of candelas (lumens per steradian). In =2eG j'} radiometric units, an intensity plot is in units of watts per steradian. Candela plots Z*|qbu) are commonly used in the design of illumination systems, especially those used in NN W* the far field. )#dP: Candela data can be collected from ray sets of Missed rays, rays Exiting a surface )rs);Pl or rays Incident on a surface. Missed rays are a collection of all rays that “leave” ^4yFLqrC the model and “go off to infinity.” Exiting rays are the collection of ray segments ewtoAru following the intersection point of a ray at a surface. Due to ray splitting, several hQfxz,X ray segments may contribute to the candela data for each incident ray. Incident =kvYE,,g_ rays are the collection of ray segments which intersect the selected surface. No <3>Ou(F surface selection is required for Missed rays but one is necessary for Exiting and *lIK?" mo Incident rays. JtU/%s The candela plots represent flux versus angle and can be smoothed using the ,9f$an Candela Options dialog box. The iso-candela plots can be presented as false vF=d`T< color maps or contour plots. The distribution plots are graphs of cross-sectional %!HmtpS curves through the candela distribution. J,E'F!{ The orientation of the candela plots is determined by the Normal Vector and the eID"&SSU Up Vector, as specified in the Analysis|Candela Options dialog box. The %o+VZEH3 normal vector specifies the axis of the candela plot and the up vector specifies |!)3[<. “which way is up.”