附录 E
（资料性）
示例
E.6.1 - 带多个项的映射形状（Mapped Shape With Multiple Items）
示例概述（Example overview）
本示例演示了使用映射项表示建筑构件代理简单几何形状的各种方式。所有示例文件使用相同的扫掠实体表示映射来定义形状（1m×1m×2m的方块）。
示例IFC文件提供的基本结构包括：
- 由以下提供的数据集基本上下文： IfcProject（项目） 及引用实体：
- IfcOwnerHistory（所有者历史） 提供创建项目数据集的用户、应用程序及时间戳；
- IfcGeometricRepresentationContext（几何表示上下文） 提供通用上下文，包括表示类型、维度、坐标系和精度；
- IfcUnitAssignment（单位分配） 提供数据集使用的默认单位，
- 由单个以下实体提供的项目基本空间结构： IfcBuilding（建筑） 及引用实体：
- IfcLocalPlacement（局部定位） to create the local object coordinate system of the building being the parant coordinate system for all objects contained within the building;
- IfcRelAggregates（聚合关系） 用于将 IfcBuilding（建筑） to the IfcProject（项目） 链接为项目空间结构的最上层项，
- 由单个以下实体提供形状表示的代理元素： IfcBuildingElementProxy（建筑构件代理） 及引用实体：
- IfcLocalPlacement（局部定位） 用于创建代理相对于建筑物对象坐标系的局部对象坐标系；
- IfcProductDefinitionShape（产品定义形状） 用于在局部对象坐标系中定义几何形状。
根据模型视图定义，在实际交换场景中可能不允许使用某些表示类型。
映射表示可由放置多个带或不带笛卡尔变换的映射表示的映射项生成。
表示映射——一个简单方块——在建筑构件代理的局部对象坐标系中被插入四次作为映射项。每个项均通过绕目标坐标系Z轴旋转45度进行变换。
IFC-SPF 源代码（IFC-SPF source）
ISO-10303-21;
HEADER;
/* NOTE a valid model view name has to be asserted, replacing 'notYetAssigned' ----------------- */
FILE_DESCRIPTION(
( 'ViewDefinition [notYetAssigned]'
,'Comment [manual creation of example file]'
)
,'2;1');
/* NOTE standard header information according to GB/T 16656.21 ---------------------------------- */
FILE_NAME(
'mapped-shape-with-multiple-items.ifc',
'2011-11-07T18:00:00',
('redacted'),
('redacted'),
'redacted',
'redacted',
'reference file created for the IFC4 specification');
FILE_SCHEMA(('IFC4X3_ADD2'));
ENDSEC;
DATA;
/* --------------------------------------------------------------------------------------------- */
/* general entities required for all IFC data sets, defining the context for the exchange ------ */
#100= IFCPROJECT('0xScRe4drECQ4DMSqUjd6d',#110,'proxy with multiple transformed representation',$,$,$,$,(#201),#301);
/* single owner history sufficient if not otherwise required by the view definition ------------ */
/* provides the person and application creating the data set, and the time it is created ------- */
#110= IFCOWNERHISTORY(#111,#115,$,.ADDED.,1320688800,$,$,1320688800);
#111= IFCPERSONANDORGANIZATION(#112,#113,$);
#112= IFCPERSON($,'redacted','redacted',$,$,$,$,$);
#113= IFCORGANIZATION($,'redacted',$,$,$);
#115= IFCAPPLICATION(#113,'redacted','redacted','redacted');
/* each IFC data set containing geometry has to define a geometric representation context ------ */
/* the attribute 'ContextType' has to be 'Model' for 3D model geometry ------------------------- */
#201= IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.0E-5,#210,$);
/* the attribute 'ContextIdentifier' has to be 'Body' for the main 3D shape representation ----- */
#202= IFCGEOMETRICREPRESENTATIONSUBCONTEXT('Body','Model',*,*,*,*,#201,$,.MODEL_VIEW.,$);
#210= IFCAXIS2PLACEMENT3D(#901,$,$);
/* each IFC data set containing geometry has to define at absolute minimum length and angle ---- */
/* here length is milli metre as SI unit, and plane angle is 'degree' as non SI unit ----------- */
#301= IFCUNITASSIGNMENT((#311,#312));
#311= IFCSIUNIT(*,.LENGTHUNIT.,.MILLI.,.METRE.);
#312= IFCCONVERSIONBASEDUNIT(#313,.PLANEANGLEUNIT.,'degree',#314);
#313= IFCDIMENSIONALEXPONENTS(0,0,0,0,0,0,0);
#314= IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453293),#315);
#315= IFCSIUNIT(*,.PLANEANGLEUNIT.,$,.RADIAN.);
/* each IFC data set containing elements in a building context has to include a building ------- */
/* at absolute minimum (could have a site and stories as well) --------------------------------- */
#500= IFCBUILDING('2FCZDorxHDT8NI01kdXi8P',$,'Test Building',$,$,#511,$,$,.ELEMENT.,$,$,$);
/* if the building is the uppermost spatial structure element it defines the absolut position -- */
#511= IFCLOCALPLACEMENT($,#512);
/* no rotation - z and x axes set to '$' are therefore identical to "world coordinate system" -- */
#512= IFCAXIS2PLACEMENT3D(#901,$,$);
/* if the building is the uppermost spatial structure element it is assigned to the project ---- */
#519= IFCRELAGGREGATES('2YBqaV_8L15eWJ9DA1sGmT',$,$,$,#100,(#500));
/* shared coordinates - it is permissable to share common instances to reduce file size -------- */
#901= IFCCARTESIANPOINT((0.,0.,0.));
#902= IFCDIRECTION((1.,0.,0.));
#903= IFCDIRECTION((0.,1.,0.));
#904= IFCDIRECTION((0.,0.,1.));
#905= IFCDIRECTION((-1.,0.,0.));
#906= IFCDIRECTION((0.,-1.,0.));
#907= IFCDIRECTION((0.,0.,-1.));
#908= IFCDIRECTION((1.,1.,0.));
#909= IFCDIRECTION((-1.,1.,0.));
/* --------------------------------------------------------------------------------------------- */
/* proxy element with mapped representation, assigned to the building -------------------------- */
/* --------------------------------------------------------------------------------------------- */
#1000= IFCBUILDINGELEMENTPROXY('1kTvXnbbzCWw8lcMd1dR4o',$,'P-1','sample proxy',$,#1001,#1010,$,$);
/* proxy element placement relative to the building -------------------------------------------- */
#1001= IFCLOCALPLACEMENT(#511,#1002);
/* set local placement to 1 meter on x-axis, and 0 on y, and 0 on z axes ----------------------- */
/* no rotation - z and x axes set to '$' are therefore identical to those of building ---------- */
#1002= IFCAXIS2PLACEMENT3D(#1003,$,$);
#1003= IFCCARTESIANPOINT((1000.,0.,0.));
/* proxy element shape representation ---------------------------------------------------------- */
#1010= IFCPRODUCTDEFINITIONSHAPE($,$,(#1020));
/* a single shape representation of type 'MappedRepresentation' is included -------------------- */
/* it contains four mapped items, each refering to the same representation map ----------------- */
#1020= IFCSHAPEREPRESENTATION(#202,'Body','MappedRepresentation',(#1021,#1031,#1041,#1051));
/* Cartesian transformation of the mapped item ------------------------------------------------- */
/* all with rotation by 45' in xy plane and non uniform scaling: x=0.5, y=0.5, z=1.0 ----------- */
/* 1. mapped item at 0.,0.,0. of local object coordinate system -------------------------------- */
#1021= IFCMAPPEDITEM(#5010,#1022);
#1022= IFCCARTESIANTRANSFORMATIONOPERATOR3DNONUNIFORM(#908,#909,#901,0.5,#904,0.5,1.);
/* 2. mapped item at 1000.,0.,0. of local object coordinate system ----------------------------- */
#1031= IFCMAPPEDITEM(#5010,#1032);
#1032= IFCCARTESIANTRANSFORMATIONOPERATOR3DNONUNIFORM(#908,#909,#1033,0.5,#904,0.5,1.);
#1033= IFCCARTESIANPOINT((1000.,0.,0.));
/* 3. mapped item at 0.,1000.,0. of local object coordinate system ----------------------------- */
#1041= IFCMAPPEDITEM(#5010,#1042);
#1042= IFCCARTESIANTRANSFORMATIONOPERATOR3DNONUNIFORM(#908,#909,#1043,0.5,#904,0.5,1.);
#1043= IFCCARTESIANPOINT((0.,1000.,0.));
/* 4. mapped item at 1000.,1000.,0. of local object coordinate system -------------------------- */
#1051= IFCMAPPEDITEM(#5010,#1052);
#1052= IFCCARTESIANTRANSFORMATIONOPERATOR3DNONUNIFORM(#908,#909,#1053,0.5,#904,0.5,1.);
#1053= IFCCARTESIANPOINT((1000.,1000.,0.));
/* --------------------------------------------------------------------------------------------- */
/* proxy element type with swept solid shape representation ------------------------------------ */
/* --------------------------------------------------------------------------------------------- */
#5000= IFCBUILDINGELEMENTPROXYTYPE('241tWGhBr3rvJJzQGOOY_x',$,'Type-P',$,$,$,(#5010),$,$,.NOTDEFINED.);
#5010= IFCREPRESENTATIONMAP(#5011,#5100);
#5011= IFCAXIS2PLACEMENT3D(#901,$,$);
#5100= IFCSHAPEREPRESENTATION(#202,'Body','SweptSolid',(#5021));
/* based on a profile (or cross section) of 1m by 1m being extruded by 2m ---------------------- */
#5021= IFCEXTRUDEDAREASOLID(#5022,$,#5034,2000.);
#5022= IFCRECTANGLEPROFILEDEF(.AREA.,'1m x 1m rectangle',$,1000.,1000.);
/* extrusion body is placed centric with no rotation inside the object coordinate placement ---- */
/* extrusion position z = default = (0.,0.,1.), x = default = (1.,0.,0.) ----------------------- */
/* since IFC4 this is the default, therefore the Position can be nil --------------------------- */
/* the extrusion if perpendicular to the profile - i.e. along the positive z-axis -------------- */
#5034= IFCDIRECTION((0.,0.,1.));
/* proxy element assigned to the building ------------------------------------------------------ */
#10000=IFCRELCONTAINEDINSPATIALSTRUCTURE('2TnxZkTXT08eDuMuhUUFNy',$,'Physical model',$,(#1000),#500);
/* proxy type - assignment to proxy occurrence ------------------------------------------------- */
#10100= IFCRELDEFINESBYTYPE('0DR6_plxf08eQ9Y0V0n$sV',$,$,$,(#1000),#5000);
/* proxy type - declared within the project ---------------------------------------------------- */
#10200= IFCRELDECLARES ('1J7MBi$pT9ogxwD7fkPsrp',$,$,$,#100,(#5000));
ENDSEC;
END-ISO-10303-21;