IfcLightSourceDirectional
Definition from ISO/CD 10303-46:1992: The light source
directional is a subtype of light source. This entity has a light source
direction. With a conceptual origin at infinity, all the rays of the light are
parallel to this direction. This kind of light source lights a surface based on
the surface's orientation, but not position.
Definition from ISO/IEC 14772-1:1997: The directional light node
defines a directional light source that illuminates along rays parallel to a
given 3-dimensional vector. Directional light nodes do not attenuate with
distance. Directional light nodes are specified in the local coordinate system
and are affected by ancestor transformations.
NOTE: Corresponding STEP entity:
light_source_directional. Please refer to ISO/IS 10303-46:1994, p. 32 for the
final definition of the formal standard.
NOTE: In addition to the
attributes as defined in ISO10303-46 the additional property from ISO/IEC
14772-1:1997 (VRML) AmbientIntensity and Intensity are inherited
from the supertype.
HISTORY: This is a new entity
in IFC 2x, renamed and enhanced in IFC2x2.
EXPRESS specification:
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| ENTITY IfcLightSourceDirectional
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Attribute definitions:
| Orientation
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Definition from ISO/CD 10303-46:1992: This direction is the direction of the light source.
Definition from VRML97 - ISO/IEC 14772-1:1997: The direction field specifies the direction vector of
the illumination emanating from the light source in the local coordinate system. Light is emitted along
parallel rays from an infinite distance away.
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Inheritance graph
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| ENTITY IfcLightSourceDirectional;
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