IfcSurfaceStyleElementSelect

BACnet MVD

#### IfcSurfaceStyleElementSelect

Natural language names

| Surface Style Element Select

##### Semantic definitions at the type

Type definition

The IfcSurfaceStyleElementSelect provides a selection between different surface styles, including IfcSurfaceStyleRendering for rendering properties, IfcSurfaceStyleLighting, which holds the exact physically based lighting properties for lighting based calculation algorithms (as the opposite to the rendering based calculation), the IfcSurfaceStyleRefraction (for more advanced refraction indices) and IfcSurfaceStyleWithTextures to allow for image textures applied to surfaces. In addition an IfcExternallyDefinedSurfaceStyle can be selected that points into an external rendering material library.

> NOTE The IfcSurfaceLightingProperties are needed for exact lighting calculation, because physically based lighting calculation algorithms need exact physically based parameters. The factors in IfcSurfaceStyleRendering lack the physical base, they are intended for rendering calculations, but a lighting calculation based software cannot use these values.

> NOTE Definition according to ISO/CD 10303-46:1992
> The surface style element select is a selection of the different surface styles to use in the presentation of the side of a surface.

> NOTE Type adapted from surface_style_element_select defined in ISO10303-46.

> HISTORY New select type in IFC2x2.

Select definition

Type | Description
--- | ---
IfcSurfaceStyleShading |
IfcSurfaceStyleLighting |
IfcSurfaceStyleWithTextures |
IfcExternallyDefinedSurfaceStyle |
IfcSurfaceStyleRefraction |

##### Formal representations

XML Specification
`<xs:group name="IfcSurfaceStyleElementSelect">
<xs:choice>
<xs:element ref="ifc:IfcExternallyDefinedSurfaceStyle"/>
<xs:element ref="ifc:IfcSurfaceStyleLighting"/>
<xs:element ref="ifc:IfcSurfaceStyleRefraction"/>
<xs:element ref="ifc:IfcSurfaceStyleShading"/>
<xs:element ref="ifc:IfcSurfaceStyleWithTextures"/>
</xs:choice>
</xs:group>
`
EXPRESS Specification
`TYPE IfcSurfaceStyleElementSelect = SELECT (
IfcSurfaceStyleShading,
IfcSurfaceStyleLighting,
IfcSurfaceStyleWithTextures,
IfcExternallyDefinedSurfaceStyle,
IfcSurfaceStyleRefraction);
END_TYPE;

EXPRESS-G diagram

`

References: IfcSurfaceStyle

Link to this page