Defined in File Ifc4.h
This struct is a nested type of Struct Ifc4.
There are three kinds of light distribution curves, according to Standard CEN TC 169, prEN 13032-1, CIE 121:
TYPE_A: Type A is basically not used. For completeness the Type A Photometry equals the Type B rotated 90° around the Z-Axis counter clockwise. TYPE_B: Type B is sometimes used for floodlights. The B-Plane System has a horizontal axis. B-Angles are valid from -180° to +180° with B 0° at the bottom and B180°/B-180° at the top, β-Angles are valid from -90° to +90°. (See Figure 302.) TYPE_C: Type C is the recommended standard system. The C-Plane system equals a globe with a vertical axis. C-Angles are valid from 0° to 360°, γ-Angles are valid from 0° (south pole) to 180° (north pole). (See Figure 302.)
B-Type System C-Type System
Figure 302 — Light distribution curves
HISTORY This is a new enumeration in IFC2x2.