给个英文的.个人理解可能会有点出入.基本上是这个意思. p4'
.1.@ V]=22Cxi'~ A candela plot is a plot of luminous intensity, or flux per solid angle. In photometric P6:9o}K6 units, a luminous intensity plot is in units of candelas (lumens per steradian). In o.+;]i}D radiometric units, an intensity plot is in units of watts per steradian. Candela plots |VBt:dd< are commonly used in the design of illumination systems, especially those used in TR"C<&y$j the far field. [2%[~&4 Candela data can be collected from ray sets of Missed rays, rays Exiting a surface :RaQ
=C or rays Incident on a surface. Missed rays are a collection of all rays that “leave” Ot=jwvw the model and “go off to infinity.” Exiting rays are the collection of ray segments $^Fl*:6 following the intersection point of a ray at a surface. Due to ray splitting, several {keZ_2 ray segments may contribute to the candela data for each incident ray. Incident OxlA)$.hpu rays are the collection of ray segments which intersect the selected surface. No :cT)M(o surface selection is required for Missed rays but one is necessary for Exiting and 7FB?t<x Incident rays. m5\T, The candela plots represent flux versus angle and can be smoothed using the w+M/VsL Candela Options dialog box. The iso-candela plots can be presented as false gD,&TW color maps or contour plots. The distribution plots are graphs of cross-sectional j#NyNv(jE1 curves through the candela distribution. ]%\,.&=hT The orientation of the candela plots is determined by the Normal Vector and the ,UNb#=it Up Vector, as specified in the Analysis|Candela Options dialog box. The !NXjax\r normal vector specifies the axis of the candela plot and the up vector specifies pGbfdX
“which way is up.”