Work with smart objects

To enable the Pulsars to be tracked, you create smart objects in Evoke for each Pulsar in your system.

For composite smart objects, the number of smart clusters is indicated by the number of pattern preview icons.

The following topics explain how to work with smart objects.

See also the Vicon video:

Create smart objects

To enable the Pulsars to be tracked, you must create smart objects in Evoke for them.

Each smart object is assigned a marker pattern, which is sent to the linked Pulsar.

When you select a smart object, its linked Pulsar device is also selected and its status lights display a selection sequence. The object is also selected in the 3D View.

In the System panel, the Pulsar connection icons on the linked Pulsars turn green as they are assigned patterns by the smart objects.

When you create a smart object, you can select the appropriate template for your smart object and you must link the smart object to the relevant Pulsar(s) to enable tracking.

In addition to the Pulsar template, templates are supplied for the Vicon headset mount for supported headsets: the Oculus Rift, HP Reverb and HTC Vive. The templates are pre-configured with sections corresponding to the Pulsar slots at the top and front of the headset, and the smart object origin set to the optical origin of the headset. Templates for the Vicon hat and backstrap are also supplied.

If required, you can create additional templates (see Use smart object templates).

To create a smart object:

1. In the Tracking Setup panel, in the Smart Object field, enter a unique name for the new smart object, ensure that the required template is selected and then click the Create button.

   

   The new smart object is displayed at the top of the Smart Objects section in the Tracking panel.

   

   It has the name you entered and is automatically assigned a unique pattern. Because no device is associated with it yet, a caution icon (yellow triangle) and unlinked Pulsar icon are displayed next to it. To enable tracking, you must link the smart object to a Pulsar.
2. In the Properties pane, go to the Smart Clusters section and in the Device field, select the Pulsar that you want to associate with this smart object.If you are using the template supplied for the Vicon headset mount for a supported headset, you must select a device for both Pulsars.

   

3. Enter the remaining details for the smart object (color, mesh, etc).
   The mesh is an FBX file with the mesh skinned to a Root bone. You can use the installed meshes that are displayed when you click on the Mesh list, or your own FBX files, saved to C:\Users\Public\Documents\Vicon\PropMeshes.

Rename smart objects

You may need to rename smart objects, for example, to match their intended location (eg, Green_LeftHand or Red_RightFoot). You can rename smart 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 smart object; or
     • Right-click the smart object and then select Rename; or
     • Select the smart object and press F2.
   Or
   • In the Tracking Setup panel, click in the Smart Object field.
2. Enter a unique new name for the smart object.

Confirm tracking and labeling

After you have created the required smart objects, make sure they're displayed in the 3D View, with labels matching the smart object names.

Cluster and smart object settings are stored in the System file. Its default location is:

C:\Users\Public\Documents\Vicon\Evoke1.#\LastRun\userName\LastRun.System

Object settings are stored in the Subjects file. Its default location is:

C:\Users\Public\Documents\Vicon\Evoke1.#\LastRun\userName\Subjects.mcp

Settings are auto-saved periodically when changes are made as well as when you exit Evoke.

Reassign smart object patterns

The number of unique patterns available for tracking without using proximity grouping is limited to:

• 56 patterns when using 5 from 8 markers; or
• 70 patterns when using 4 from 8 markers

To use more than 70 patterns, see Use proximity-based tracking.

If more smart objects are created than available patterns, the excess smart objects are assigned pattern 0 (no markers on), and show a warning in the Tracking panel. The linked Pulsars also show a cyan status icon in the System panel.

The pattern set is chosen automatically, depending on the number of Pulsar clusters selected when creating smart objects.

If you later change the number of smart objects, you can reassign patterns to all loaded smart objects and if necessary change the pattern set. To do this:

• On the Edit menu, click Assign Smart Object Patterns.

  

Smart object pattern management

You can assign patterns to Smart Objects in either of these ways:

• Enable Evoke to automatically assign a unique pattern to each smart object. This is the default option.
  To check that Evoke is managing smart object patterns:
  
  • Openthe Preferences dialog box (Settings > Preferences or press Shift-P) and in User Preferences, scroll to the Objects section and ensure that Automatically manage smart object patterns is selected.

    

    When this option is selected, Evoke automatically manages the patterns for smart objects whenever a smart object is created. Note that:

    • The new smart object is assigned a unique pattern from the current pattern set, if one is available.

    • The initial pattern set is 5-from-8, meaning that 5 of the Pulsar marker LEDs are turned on. There are 56 unique patterns in this set.

    • If you require more than 56 patterns, Evoke switches to the 4-from-8 pattern set. There are 70 unique patterns in this set.

    • Any smart objects that aren't using the correct pattern set are assigned a new pattern.

    • If you require more than 70 patterns, excess smart objects are assigned pattern 0, meaning they will not turn on any markers and can't be tracked.

• Assign patterns using the Evoke API (see Vicon Evoke API & automation). In this case, if you don't want Evoke to make changes to the patterns, in the Preferences dialog box, scroll to the Objects section and clear Automatically manage smart object patterns.
  

Note that:

• Active smart objects are prioritized for pattern assignment over inactive smart objects.
• A smart object is active if it is enabled and each smart cluster slot is linked to a device.
• Inactive smart objects are still assigned patterns if enough patterns are left after they have been assigned to the active smart objects.

Merge smart objects

To get good tracking performance from different viewpoints or under occlusion, you may need to attach multiple Pulsar clusters or extra markers to a single rigid object. In particular, if you are using VR headsets and/or guns or similar props, you may benefit from the better rotational stability and/or occlusion resistance offered by combining multiple Pulsar clusters.

To merge smart objects:

1. Create smart objects as normal (see Create smart objects).

   

2. In the Tracking panel, select the smart objects that will contribute to the merged object, right-click and then click Merge smart objects.
   In the Tracking panel, the merged smart object is displayed with multiple pattern preview icons.

   
   

3. Enter a name for the merged smart object.

   The selected smart objects are replaced with a single composite smart object, retaining the origin of the first selected object.

   

   In the Properties pane for the merged smart object, the properties of the combined objects are displayed (the smart object that was selected last appears first in the Smart Clusters section). Note that in the following example, the Advanced properties are displayed.

   

Merge additional markers into smart objects

In addition to merging smart objects (see Merge smart objects), you can combine them with additional markers to create more complex objects while maintaining smart object functionality (for example, adjustable patterns). This enables smart objects to benefit from more widely spaced LEDs, enhancing tracking performance and visibility.

To merge additional markers into a smart object:

1. In the 3D View, select the required smart object and the additional markers (Alt+drag or drag only, if the option Alt key to select in views is cleared in Preferences).

   
   
   

2. In the Tracking panel, right-click on the object and select Merge Smart Objects.

   

   In the 3D View, the merged object is displayed.

   

   In the Tracking panel, the composite object can be identified with a new icon next to the object name.

   
   
   

   You can save this composite object as a template and use it as a family of objects, each with a unique smart object pattern for identification.
   Note that because these additional markers are not controlled by a smart object, they cannot be enabled or disabled with the rest of the composite object.

Split a merged smart object

If you need to split smart objects that you have previously merged, you can separate them again.

To split a merged smart object:

1. In the Tracking panel, select the merged smart object.
2. Right-click the merged object and then click Split Smart Objects.
   The separated objects are given the name of their device slot (eg, Top, Front), appended with a number if that name is already in use.

Use smart object templates

Smart object templates let you easily create smart objects for Pulsars and supported accessories. Evoke comes with templates for the Vicon-supplied accessories Backstrap, Hat, and supported headsets: Oculus Rift, HP Reverb and HTC Vive (the templates for the clip for the headset, with two Pulsar mounts), as well as for a single Pulsar.

You can also create custom templates, for example, for a backpack, to speed up the creation of merged smart objects.

The template stores information about each device and its relative orientation, together with the merged object properties (object preset, mesh, color and root segment name). Smart objects that are created from this template are automatically assigned patterns, so you only need to select the required Pulsar from the Device field to enable tracking.

You can assign to any objects a mesh that is displayed in the 3D View.

To create a template for a merged smart object

1. Create the merged smart object (see Merge smart objects) with the required mesh and other attributes.
2. In the Tracking panel, right-click the composite smart object and then click Export Template.
3. In the Export Smart Object Template dialog box, enter a name for the template and then click Save.
   The template is saved into the default location:
   C:\Users\Public\Documents\Vicon\SmartObjectTemplates
   You can now use your template to create further smart objects as described next.

To apply a custom template:

1. Create a smart object as described in Create smart objects, but instead of Pulsar, select your custom template:

   
   
   

2. In the Tracking panel, with the new smart object selected, go to the Smart Clusters section of the Properties, click the Device lists and select the required Pulsars.

   

   When you have entered these details, the object is displayed in the 3D View with the mesh and correct orientation.

Add a mesh to a smart object

Adding a mesh to smart 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 smart 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 smart object's origin

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

Note that you only need to change the origin of smart objects that you create manually or from custom templates: the built-in smart object templates already have the correct origin set.

1. To activate the object manipulator:
   1. To pause Evoke, click Enter Review at the bottom right of the Workspace.
   2. Select the smart object.

   3. In the 3D View, click the object manipulator button.

      

2. In the Workspace either:
   
   • Drag the manipulator to move or rotate the smart object to the required location; or

   • Enter the required values in the Translation and/or Rotation fields;
     
     
     
     

     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 one of the buttons at the right of the Object Manipulator heading .

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 and then expand Alignment Tool at the bottom. For more information, see Understand the alignment tool.

Swap clusters

Use the Swap Clusters option when you need to replace a device, for example, if you need to change one of your Pulsars because its battery charge is low or if you have created a smart object using one of the supplied templates (OculusRift, etc) and need to link a physical device to its smart object.

1. Ensure the replacement Pulsar is in the volume.
2. If it doesn’t already have a smart object, create one for it (see Create smart objects).
3. With the new smart object selected, hold down the Ctrl key and select the smart object for the Pulsar that you want to replace. (Note that selecting the device in the System tree also selects the smart object if one is present.)
4. In the Tracking panel, do one of the following:
   • For single-slot smart objects: Right-click and select Swap Cluster.
   • For composite smart objects (ie, if the second smart object has multiple slots): Right-click, point to Swap Cluster and select the device slot that is to be affected by the swap. (The other selected smart object must have a single device slot.)

   The new Pulsar is used by the existing Smart Object or slot.

Remove selected devices

To avoid listing unwanted devices, you can remove selected missing cluster(s) from the list of devices in the System panel.

To remove unwanted devices:

1. In the System panel, right-click on the device(s) that you want to remove.
2. Point to Remove, and then click Selected.