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20252453-T-424 项目

4.2.2.1.4 余弦螺旋过渡段(Cosine Spiral Transition Segment)

余弦螺旋过渡段是螺旋线的一种特殊情况,其曲率变化率为余弦函数,并且各项取决于从拐点开始测量的长度 L。参数值定义为偏角,即方位角 Θ。

其各项取决于段长度 L 的值: 余弦项 = L 常数项 = 1

下图展示了应用此概念时使用的通用类和关系。

<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a> IfcCurveSegment      LayerAssignment [0:1]      StyledByItem [0:1] 1. Transition [1:1]      UsingCurves [1:?] 2. Placement [1:1] 3. SegmentStart [1:1] 4. SegmentLength [1:1] 5. ParentCurve [1:1] <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a> IfcCosineSpiral      LayerAssignment [0:1]      StyledByItem [0:1] 1. Position [1:1] 2. CosineTerm [1:1] 3. ConstantTerm [0:1] <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a>:ParentCurve1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a>:IfcCosineSpiral0 IfcLengthMeasure_0 IfcLengthMeasure <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a>:SegmentStart1->IfcLengthMeasure_0:IfcLengthMeasure0 IfcLengthMeasure_1 IfcLengthMeasure <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a>:SegmentLength1->IfcLengthMeasure_1:IfcLengthMeasure0 <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcLengthMeasure.htm'>IfcLengthMeasure</a> IfcLengthMeasure <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a>:CosineTerm1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcLengthMeasure.htm'>IfcLengthMeasure</a>:IfcLengthMeasure0 <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcReal.htm'>IfcReal</a> IfcReal <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a>:ConstantTerm1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcReal.htm'>IfcReal</a>:IfcReal0
Figure 4.2.2.1.4.A