Work with basic objects

To enable tracking of your props, you create basic objects in 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.

Basic object

Smart Object

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.

See also the Vicon video:

Display the required items in the Tracking panel

By default, all items are displayed in the Tracking panel. To display only the items needed for the current task, you can display or hide items in the Tracking panel, depending on their type.

To toggle the display of tracking items:

At the top right of the Tracking panel, click the relevant button(s):

The buttons toggle the display of:

• Basic objects (non-assigned)

• Scene meshes (non-tracked)

• Characters (including assigned objects)

• Smart Objects (non-assigned)

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.

   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).

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 (default name: Basic Object #) is displayed.

   

   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.

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.

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).

• 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.

     

• 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.

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.

In the 3D Scene 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 and then click Alignment Tool at the bottom. For more information, see Understand the alignment tool.

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 Scene, select the labeled marker that you want to remove.
2. On the Setup tab, in the Modify Object line, 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 Scene, select the required unlabeled marker.
2. At the top of the Tracking panel, CTRL+click to select the required basic object.
3. On the Setup tab, in the Modify Object line, click Add Marker.
   The unlabeled marker is now labeled and added to the selected object.

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.

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). 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.