An assembly contains the basic objects for dynamic simulation: parts, constraints and graphics. It is built and used by mechanical engineers and contains all that is necessary to implement the mechanical design of a component. It is a object that reacts to mechanical and data inputs. The Assembly can be added to a scene or to a mechanism.

Assemblies can also contain nested assemblies, which are then referred to as sub-assemblies for clarity.

Assemblies simplify the creation of mechanisms such as vehicles, cranes, or robots. You can transform an entire assembly, or rotate it to view it in a different perspective.

The figure below indicates where assemblies are located in the Vortex® Studio hierarchy.

An assembly consists of parts and their collision geometries, constraints, and attachment points but can also include other objects such as dynamics extensions, scripts, VHL interfaces and graphics.

Building Assemblies from a Graphics Gallery or a 3D Model

Given a graphic asset, or 3D reference model, Vortex® can generate the dynamics components (parts and collision geometries) to match.

If you are not already in the Assembly editor, either open an existing assembly or create a new one.
This assembly will hold the parts built from the graphic asset (to be imported in the next steps).
Do one of the following:
1. Insert 3D models through a Graphics Gallery (recommended).
2. In the Toolbox, double-click 3D Model....
3. In the Toolbox, double-click Galleries From Files.

For b., the Import 3D Models panel appears.

Do one of the following:
- Find the 3D model file you want to use under the File System section and double-click it.
- Click the Browse button under the File System tree and double-click the 3D model file you want to use.

Valid asset file formats include *.flt, *.osg, *.ive, and *.cive.

For a complete list of formats, have a look at the complete list of supported 3d model formats..

The Vortex Editor imports the 3D model file into a new Graphics Gallery. The Graphics Gallery appears in the 3D View and you can now find the node tree for the model under the Explorer Panel

For c., the Add Graphics Gallery panel appears.

Do one of the following:
- Find the graphics gallery file you want to use under the File System section and double-click it.
- Click the Browse button under the File System tree and double-click the graphics gallery file you want to use.
The Graphics Gallery appears in the 3D View and you can now find the node tree for the model under the Explorer Panel

Once the Graphic Gallery is shown and the node tree is in the Explorer panel, you can create parts. For each part you want to create, follow the instructions under Building Parts from a 3D Model.
When you are finished creating parts, save the Assembly.

If the graphic file is not found, no graphic will be loaded. An error might occur during runtime simulation causing the simulation to not run properly

Creating Assemblies and Adding Parts Manually

Creating assemblies and parts from a 3D model is by far the best option; however, sometimes you need to create assemblies and add parts to them manually.

In this case, you can follow the instructions in this section.

If you are not already in the Assembly editor, either open an existing assembly or create a new one.
Follow the instructions in Creating Parts and Geometries Manually

Working with Linking Interfaces

Similar to the Vortex® High Level (VHL) Interface for mechanism, the Linking Interface exposes a defined subset of the assembly's internal fields as inputs, outputs and parameters. However, the Linking Interface also contains an Attachment Point for physical connection and allows tagging.

The values of the Linking Interface are exposed so that a systems integrator can modify these values without knowledge of the internal complexity of the Assembly. Additionally, non-modifiable properties and their respective values and parameters are protected during modification, testing, and validation stages.

Linking Interface properties are accessible at the Assembly, Mechanism and Scene level, but they can only be created in the Assembly editor.

Linking Interface properties includes:

Inputs: These are properties used to operate the Assembly during simulation.
Outputs: These are properties used to get and read information about the outcomes of the simulation.
Parameters: These are the properties that define or specify Assembly behavior or used to control and condition the way an Assembly is simulated. They are typically agreed upon and provided at the design stage of the development of a given Assembly.

In addition, Linking Interfaces also includes two additional fields that are required to properly connect with another Linking Interface.

Interface Tag: Tagging is important as it is a simple way to control linking without forcing it on the user. While a Linking Interface with no tag can connect to any other Linking Interface, a pair of Linking Interface with different tag won't be able to create both the data connection as well as the physical connection.
Attachment Point: This field represents the Attachment Point that will be used to create an Attachment between the Assemblies. No connection can occur if the field is empty or invalid.

Creating a New Linking Interface

To create a Linking Interface, you must first open the Assembly editor. The extension can be found inside the Simulation section of the Toolbox. To create a new instance, either double-click on the Linking Interface icon or drag it into the 3D View window.

The Linking Interface Editor allows you to expose properties in the Linking Interface.

You can also use it to rename properties and add meaningful descriptions for each property.

After creating a Linking Interface from the Toolbox, the Linking Interface Editor should open. If it was closed, double-click on the Linking Interface item from the Explorer tree to open its Linking Interface Editor page.
In the Explorer tree, click any object that contains properties (parts, constraints, controllers, wheel components, and collision geometries). Their properties appear in the Property panel on the right.
From the Property panel, drag and drop the property you want to expose onto either the Input, Output, or Parameters section of the Interface Editor.

Read-only input and parameter properties cannot be exposed in the Linking Interface Editor.
Now you can perform any of these tasks to customize your exposed parameter:
- By default, the exposed parameter uses the name of the internal property. To use a different name, double-click on the Name cell and type the new name.
- To add a description for the parameter, double-click on the Description cell and type the description. You can press the Enter or Tab key to finish editing.
- You can add minimum and maximum values for the parameter in the appropriate column. A exposed parameter can only be set the range value of the minimum and maximum value.
- To break the link between the Linking Interface and the source of the property, hover over the arrow in the Data column of the property you want to disconnect. When you see the trash can icon, click on it. The parameter still appears in the Linking Interface Editor, but the link to the reference of the data has been disconnected.
- To connect a property to an existing parameter (for example, if its link was broken), drag and drop the property onto the Data column of the target property's row.
- To delete the entire parameter entry from the Interface, select the row you want to delete and press the Delete key.
Additionally, you can add Inputs, Outputs and Parameters to the Linking Interface Editor by clicking the + button next to Category heading.
- In the resulting drop-down list, select the type of data for this new output (e.g., Integer, Boolean, String). A property of that data type is added to the table, where you can edit its details.

In addition to the Linking Interface editor, selecting a Linking Interface from the Explorer Tree will display its properties in the Properties Panel. These fields are needed in order to create a valid link between two Linking Interfaces.

Editing a Linking Interface

This procedure explains how to load a existing interface in the Linking Interface Editor.

If you are not already in the Assembly editor, open the assembly containing the Linking Interface since it can only be modified there.
From the Explorer panel, open the Linking Interface you want to open.
Right-click the Interface and select Edit from the context menu to open the Linking Interface Editor in the main window. Double-click the Interface will also work.

Each Linking target can only be bound to a single property.
To undock the Interface Editor, right-click anywhere on it and select Undock. This allows you to see the contents of the 3D View and the Interface Editor at the same time and move it around the workspace. To dock it again, right-click inside the Interface Editor window and click Dock.

What You Can Do With Assemblies

Once you have an assembly you may perform any of the following tasks: