# 2.1: Karamba3D Entities Grasshopper (GH) is an object oriented, visual scripting environment. It provides items like points, curves, surfaces, . . . for geometric computing. The full range of geometric items can be inspected in the subcategory **“Geometry”** of the toolbar section **“Params”**. Karamba3D adds seven entities for building structural models: | Entity | Typology | | ------------- | --------------------------------------------------------------------------------------- | | Model | contains all the information related to a structure | | Element | can be a beam, truss, shell or spring | | Element Set | groups together elements in a given order, makes them accessible under a common name | | Joint | defines the connectivity between neighboring elements | | Load | external action which is imposed on the structure | | Cross-section | defines a structural element’s geometry in section | | Material | provides information regarding the physical behavior of what a cross section is made of | | Support | defines how a structure connects to the ground. | Karamba3D objects behave like GH entities. * They can be stored in containers (see the **“Params”** subcategory of the **“Karamba3D”** toolbar). * When converted into text by plugging them into a panel they provide textual output regarding their fundamental properties. ## Default Settings In order to build a structural model not all of the above entities need to be present. Karamba3D assumes default settings for materials and cross sections: * If no material is given, Karamba3D chooses steel (S235 according to EC3 with$$f\_{yk} = 23.5 kN/cm^2$$) for all cross sections. * For beams the default is a circular hollow cross sections (CHS) with an outer diameter of$$114.4mm$$and a wall thickness of $$4mm$$. The default thickness of shells amounts to $$10mm$$. ## Graphical User Interface Some Karamba3D components come with graphical user interface components like radio-buttons, drop-down lists and sub-menus. Sliders on Karamba3D components have a preset number-range. Double-click on the knob to change the precision and range to your specific need. In some cases the user can select between different options at a component input (e.g. the Load-Case at a result component, or the degrees of freedom at a support-component). To select these options via ValueList-components right-click on the Karamba3D-component and select "**Expand ValueLists**" from the context menu or plug a ValueList into the corresponding input-plug. The selection of dynamic content that depends on the upstream -model (e.g. selection of load-cases) works only after the component executed at least once. So one needs to connect the mandatory input-plugs before expanding dynamic value-lists. The ModelView-, BeamView- and ShellView-components provide a short-cut for selecting color-ranges for result display: Right-click on the components and select 'Colors' from the context menu. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://manual-2.karamba3d.com/2-getting-started/2-getting-started-1/karamba3d-entities.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.