As described in Section 3 . 1 , the

As described in Section 3 . 1 , the reason for using the same Average Reflectance for all Radiance RGB components is to render a gray scale image in order to visualize only the illumination levels . For rendering a color image , Eq ( 1 ) will not be used by Revit2 Radiance ) . Revit2 Radiance also takes the custom parameter values " Specularity " and " Roughness " to write the Radiance material description . Table 4 shows the manually calculated values for the Average Reflectance for Revit material " Sash " and Fig . 13 shows the prototype output of Radiance material description . Both the prototype-generated Average Reflectance ( 0 . 73 for RGB components and the manually calculated Average Reflectance