IFC 4.3.0.0 (IFC4X3) final

8.14.2.2 IfcLightDistributionCurveEnum

8.14.2.2.1 Semantic definition

There are three kinds of light distribution curves, see Figure 1.

8.14.2.2.2 Type values

Type Description
TYPE_A

Type A is basically not used. For completeness the Type A Photometry equals the Type B rotated 90掳 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掳 to +180掳 with B 0掳 at the bottom and B180掳/B-180掳 at the top, 尾-Angles are valid from -90掳 to +90掳.

B-Type
Figure 8.14.2.2.A
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掳 to 360掳, 纬-Angles are valid from 0掳 (south pole) to 180掳 (north pole).

C-Type
Figure 8.14.2.2.B
NOTDEFINED

Not defined.

Table 8.14.2.2.C

8.14.2.2.3 Formal representation

TYPE IfcLightDistributionCurveEnum = ENUMERATION OF
	(TYPE_A
	,TYPE_B
	,TYPE_C
	,NOTDEFINED);
END_TYPE;

8.14.2.2.4 References