--- title: "Work with basic objects" canonical: "https://help.vicon.com/space/Evoke17/10818485/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 in Evoke. > Macro (excerpt-include) 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. > Macro (scroll-only) > > For more information, see: > > > Macro (toc) > Macro (scroll-pagebreak) Also, for more information, see also the Vicon video covering Basic objects. > Macro (scroll-only) > > [ > ](https://www.youtube.com/watch?v=6isTWluFZBw)> Macro (inline-external-image) > > [ > ](https://www.youtube.com/watch?v=6isTWluFZBw) > [Evoke 1.6 - Basic Objects ](https://www.youtube.com/watch?v=6isTWluFZBw) > Macro (scroll-ignore) > > > Macro (widget) ## > Macro (anchor) 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. If you're using Nova or SuperNova strands, make sure that the markers are turned on. :check_mark: **Tip** If you don't see anything in the 3D View, in the **View Filters**, ensure **Unlabeled Markers** is selected. 2. In Evoke, select at least four unlabeled reconstructions – five or more is recommended (Alt+drag or drag only, if the option ***Alt***** key to select in views** is cleared in **Preferences**). 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 Setup** panel, click the **Create** button for a basic object. A new basic object is created with labeled markers and sticks. In the **Tracking** panel, a new basic object (default name: BasicObject#) 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](https://vicon-help.atlassian.net/wiki/spaces/Evoke17/pages/10814070). 4. Enter a unique new name for the basic object. > Macro (scroll-pagebreak) ### Rename basic objects You may need to rename basic objects, for example, to match their intended location (eg, `Green_LeftHand` or `Red_RightFoot`). You can rename basic objects in either the Tracking Setup panel or the Tracking panel. **To rename smart objects:** 1. Choose whether to use the Tracking panel or the Tracking Setup panel: - In the tree at the top of the **Tracking** panel, do one of the following: - Double-click the basic object; or - Right-click the basic object and then select **Rename**; or - Select the basic object and press F2. Or - In the **Tracking Setup** panel, click in the **Basic Object** field. 2. Enter a unique new name for the smart object. > Macro (scroll-pagebreak) ## 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** panel, 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. > Macro (scroll-pagebreak) ## > Macro (anchor) 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 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 buttons to the right of the **Object Manipulator** heading > Macro (inline-media-image) . In the 3D View, you can align a selected object's axes to the global axes, a selected marker, or to the center of multiple selected markers. To do this, select the relevant object(s) or marker(s), activate the Object Manipulator > Macro (inline-media-image) and then expand **Alignment Tool** at the bottom. For more information, see [Understand the alignment tool](https://vicon-help.atlassian.net/wiki/spaces/Evoke17/pages/10817000). ## > Macro (anchor) Add or remove markers – basic objects Evoke enables you to add markers to a basic object or remove markers from a basic object. This is particularly useful, if, for example, a marker fails or falls off the object. If a marker is removed from a basic object, you can manually select and remove the marker from the reconstruction. Similarly, if a marker is added, you can assign it a label and make it part of an existing reconstruction. **To remove a marker**** from a basic object:** 1. In the **Tracking** panel, ensure that the required basic object (which must have more than four markers) is selected, and in the **3D View**, select the labeled marker that you want to remove. 2. In the **Tracking Setup** panel, go to the **Modify Object** line and click **Remove Marker**. The marker becomes unlabeled and is removed from the object. **To add an unlabeled marker to a basic object:** 1. In the **3D View**, select the required unlabeled marker. 2. At the top of the **Tracking** panel, Ctrl+click to select the required basic object. 3. In the **Tracking Setup** panel, in the **Modify Object** line, click **Add Marker**. The unlabeled marker is now labeled and added to the selected object. ## > Macro (anchor) Export a basic object as a VSK To export a basic object as a Vicon Skeleton (VSK) file: 1. On the **Tracking** panel, 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. ## > Macro (anchor) Create a custom calibration object You can use a Vicon Active Wand to quickly set up your volume coordinate system (see [Set the volume origin](https://vicon-help.atlassian.net/wiki/spaces/Evoke17/pages/10818124/Set+up+the+volume#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. For information on how to do this, see [Scale calibration and set a fixed origin](https://vicon-help.atlassian.net/wiki/spaces/Evoke17/pages/10817435).