---
title: "Work with basic objects"
canonical: "https://help.vicon.com/space/Evoke14/10158880/Work%20with%20basic%20objects"
format: markdown
---
To enable tracking of your props, you create basic objects in Evoke.

> ✅ **Tip**   
> ✅ It is easiest to use the Vicon Nova kit to mount active markers on a variety of props and use them within Evoke.

You manage objects in the **Tracking** pane, which lists all objects tracked by Evoke. You can visually distinguish basic objects from Smart Objects by their icons.

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 Basic object

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 Smart Object

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 Composite Smart Object

Basic objects have a fixed pattern, so if a marker is moved you must re-create the object.

Note that you can import VSK files for basic rigid objects.

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See also the Vicon video:

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>  [ Evoke 1.2 - Basic Objects](https://youtu.be/ENT5df3Yh8E)

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## Create basic objects

To represent your props, you create basic objects in Evoke.


**To create a basic object:**


1. Place the prop with active markers attached in the volume, making sure that the markers are turned on.
  :check_mark:** Tip**: If you don't see anything in the 3D Scene, in the **View Filters**, ensure **Unlabeled Markers** is selected
2. In Evoke, select at least four (five or more is recommended) unlabeled reconstructions.
  The orientation of the object depends on the order in which you select the reconstructions. The first is the root, the second is the axis it will point along, and the third is the Up vector for the object. If necessary, you can change this later (see [Change a basic object's origin](#ChangeBasicObjOrigin)).
3. In the **Tracking** pane, click the **Create** button for a Basic Object.
  A new basic object is created with labeled markers and sticks.
  In the **Tracking** pane, a new basic object (by default, called Basic Object #) is displayed.
  :check_mark:** Tip**: If your new object has a warning symbol (yellow triangle) next to it, to view information about the issue, hover the mouse pointer over the symbol. For more information, see Understand object evaluation.
4. To rename the basic object, in the tree at the top of the Tracking pane, either:
  - Double-click the basic object to edit the name; or
  - Right-click it and then select **Rename**; or
  - Select the basic object and press F2; or
  - Select the basic object and in the **Properties** pane below, click the **Name** field.
5. Enter a unique new name for the basic object.

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## Add a mesh to a basic object

Adding a mesh to basic objects enables you to better visualize them in the Workspace to check that they are correctly aligned and that they give the user experience that you want.

1. In the **Tracking** pane, select the basic object to which you want to add a mesh.
2. In the **Properties** pane, from the **Mesh** list, select the required mesh.
  The mesh is an FBX file with the mesh skinned to a Root bone. You can use the installed meshes, or your own FBX files, saved to *C:\Users\Public\Documents\Vicon\PropMeshes*.
  Your mesh is displayed in the 3D workspace.

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## Change a basic object's origin

The object manipulator enables you to specify a basic object's origin (ie, the center of the physical object in relation to the marker pattern that is tracked by Evoke).

1. To activate the object manipulator:
  1. Press the space bar or click the **Pause** button at the bottom right of the **Workspace** to pause Evoke.
  2. Select the basic object.
  3. In the **3D Scene** view, click the object manipulator button.
2. In the Workspace either:
  - Drag the manipulator to move or rotate the object to the required location; or
  - Enter values in the **Translation** and/or **Rotation** fields;
    When you resume streaming, the object's orientation is updated.
    :check_mark: **Tip**: To scale the Manipulator, on the numeric keypad, press + (scale up) or - (scale down).

Note that the manipulator operates in local or global space (corresponding to the object coordinate system or the world coordinate system respectively). To switch between the two, click the icon to the left of the **Object Manipulator** text.


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## Export a basic object as a VSK

To export a basic object as a Vicon Skeleton (VSK) file:

1. On the **Tracking** pane, right-click on the basic object and then select **Export**.
2. In the **Export** dialog box, browse to or enter the location for the object.
3. Save the VSK.

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Create a custom calibration object

You can use a Vicon Active Wand to set up your volume coordinate system quickly and easily (see [Set the volume origin](https://vicon-help.atlassian.net/wiki/spaces/Evoke14/pages/10158177/Calibrate+cameras#SetOrigin)). However, using a larger calibration object (for example, markers embedded in the volume floor and wall) can improve calibration stability and consistency over time.

You can create and export a custom calibration object from any basic object as described in [Create basic objects](#CreateObjects) and [Export an object as a VSK](#ExportObjAsVSK).

When you export the VSK, save it to your calibration objects folder. The default location for this is:


*C:\Users\Public\Documents\Vicon\CalibrationObjects*


You can now use it to set the origin of your volume:

1. On the **Camera Calibration** tab, make sure the Advanced options are displayed (click **Show Advanced** at the top right if necessary).
2. Ensure the **Set Volume Origin** section is expanded.
3. From the **L-Frame** list, select the object that you created.
4. Ensure **Perform Rescale** is selected.
  This ensures that the marker distances in the L-Frame object are used for volume scaling.
5. Click **Start Set Origin**.
  The button displays **Set Origin** and is unavailable until Evoke has enough data to set the origin, when the button is enabled.
  If issues are detected, Evoke displays a message in the **Set Origin** button's tooltip to help you solve the problem. For more information, see [About collecting frames](https://vicon-help.atlassian.net/wiki/spaces/Evoke14/pages/10158177/Calibrate+cameras#AboutCollectingFrames).
6. Click **Set Origin**.
  The system scale is adjusted to provide improved calibration stability and consistency.