# 3.1.8: 由索引到梁 (Index to Beam)

有时，给定的初始几何形体是一组点以及两个节点索引列表，其中每个梁的起点和终点分别具有一个条目。在这种情况下，如果仅是出于将其馈送到**“LineToBeam（由线到梁）”**运算器的目的而将这些信息转换成几何实体是很麻烦的，因为这只是取消上一步运算而已。**“IndexToBeam（由索引到梁）”**运算器（如图3.1.8.1）可接受一对节点索引列表并从中生成具有默认属性的梁。由于不需要比较节点的重合坐标，因此可大大加快模型生成速度。

![图3.1.8.1：“IndexToBeam（由索引到梁）”运算器帮助用户直接定义梁的连接信息](/files/-M9XuSFGBI12eTzgz41n)

**“IndToBeam（由索引到梁）”**运算器使得定义长度为零的元素成为可能。如果用户需要连接彼此相互接触但无需牢固固定、连接的元件，该运算器是很有用的（如剪刀，请参见第[3.3.3](/chinese_1_3_3/3-in-depth-component-reference/3.3-cross-section/3.3.3-spring-cross-sections.md)节中有关弹性元件）。

输入端口**“Z-Ori（Z方向）”**、**“Color（颜色）”**、**“Id（标识符）”**和**“CroSec（断面）”**与**“LineToBeam（由线到梁）”**运算器中的含义相同（请参阅[3.1.6](/chinese_1_3_3/3-in-depth-component-reference/3.1-model/3.1.6-line-to-beam.md)）。


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