> For the complete documentation index, see [llms.txt](https://manual-1-3.karamba3d.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://manual-1-3.karamba3d.com/chinese_1_3_3/2-getting-started/2-getting-started-1/2.3-physical-units.md).

# 2.3: 物理单位

安装Karamba3D时，用户可以指定用于输入和输出的物理单位。默认选项是公制（国际单位制基本单位）（例如，米、厘米、摄氏度、牛顿等），但Karamba3D也可以使用英制度量单位（例如，英尺、英寸、华氏度、千克力等）。

{% hint style="info" %}
用户可随时通过编辑 [“karamba.ini”](/chinese_1_3_3/troubleshooting/4.3.-miscellaneous-problems/4.1.6-changing-karamba.ini-file.md) 文件来更改要使用的单位集。
{% endhint %}

依据不同的度量单位系列，Karamba3D会将输入的几何体度量单位转换为米或英尺。当鼠标指针悬停在输入端时，工具提示中会显示运算器可接受的物理单位类型。

在创建GH定义期间更改物理单位类型可能会引发问题：Grasshopper运算器的帮助文本不会做动态更改。从公制切换到英制单位后，原本已放置在画布上的那些运算器的帮助文本保持不变。但输入值的转换则会发生变化。使用由不同物理单位设置的Karamba3D版本打开GH定义时也会遇到相同的问题。

Karamba3D自带用于预定义断面和材料的数据库。上述属性均以公制度量单位表示。在**“karamba.ini”**文件中定义的物理常数（例如“gravity（重力）”）也是如此。

在本用户手册的其余章节中，将仅使用公制单位，以方便读者阅读。如果在Karamba3D中使用英制单位和公制单位存在一定的区别，会在本文中提及。


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