Assign objects and calibrate characters

After you have created the characters in Evoke and prepared the participants (see Create characters and Prepare the participants), you can assign objects and calibrate the character for each participant in these ways:

• Automated workflow: For each character, assign one or two reference objects (typically these are the Pulsar clusters for the head or spine) to the correct slots, designating the remaining objects as auto-assignable. The remaining objects are automatically assigned to the correct slots in a single step when you calibrate the character (see Assign clusters and calibrate characters (automated workflow).) For best results, use two reference objects, although this is not essential.

  This is normally the quickest and easiest way to assign objects and calibrate characters.

  Auto-assign for object tracking only
  If only object tracking is required, you can auto-assign clusters without character solving or retargeting.

  To use this option, in the Processing panel ensure the Advanced options are displayed and in the Characters From Clusters section, select Disable Solving.

• Manual workflow: Manually assign each smart object (or basic object) to the correct slot, and finally, calibrate the character (see Assign clusters (manual workflow)).

For information on character calibration, see Calibrate characters.

Assign clusters and calibrate characters (automated workflow)

To quickly assign objects to a character and calibrate it, use the following automated workflow.

• Prepare objects for auto-assignment
• Auto-assign objects and calibrate characters

Prepare objects for auto-assignment

Prepare the objects for auto-assignment, as described in the following steps, which are required for first time setup only.

• Prepare the unassigned objects
• Prepare the reference object(s)

Prepare the unassigned objects

In the 3D View, select the unassigned objects that you want to be auto-assigned and in the Tracking panel, in the Properties pane, select Auto Assign Enabled.

In the Tracking tree, when an object has Auto Assign Enabled selected, an additional icon is displayed to indicate that the object is auto-assignable, giving you a quick visual indication of the object's status.

Prepare the reference object(s)

Assign one or (preferably) two objects (these can be smart objects, composite smart objects or basic objects) to the appropriate slots. Typically the reference objects are the Pulsar clusters for the head and/or spine.

To assign reference objects to their slots:

1. In the Tracking panel, select the reference object, and in the Properties pane ensure that Auto Assign Enabled is cleared.

   

2. Ensure the objects are positioned in the volume in a way that makes it easy to tell which one is which (you may want to place them on a person or mannequin).
3. In the 3D View or in the Tracking tree, select the object andCtrl+select its slot in the Tracking tree, then right-click either the object or the slot and select Assign Object.

   

4. Ensure the reference object is displayed in the correct slot for the character.

   

5. Auto-assign the remaining objects for the character, as described in Auto-assign objects and calibrate characters.

Auto-assign objects and calibrate characters

Ensure you have prepared both the unassigned objects and one or more reference object(s) (see Prepare objects for auto-assignment), and the participants (see Prepare the participants).

At the start of each experience, auto-assign objects and calibrate each character, as described in these steps:

1. Get the participant(s) to stand in the capture volume in a neutral pose (known as an N-pose), which is a relaxed pose with the hands by the sides.

   The following image shows a character in a neutral pose (to show the pose clearly, the character has been calibrated).

   

2. Ensure that the following objects are attached to each participant:

   • One or (preferably) two reference object(s). Typically these are the Pulsar clusters for the head or spine. For best results, use both, although this is not essential.

   • Auto-assignable objects on their other limbs (eg, hands and feet).

     

3. In the Tracking panel, select one or more participant's characters, right-click and then click Calibrate (or, to calibrate all characters, press the shortcut Shift+C).

   

   The objects are 'fitted', based on their positions in relation to the available and unpopulated slots, and assigned correctly. If you're solving a character, it is displayed with a skeleton.

   

Assign clusters (manual workflow)

1. As described in the automated workflow, set up the name, template and retarget file, and select the required templates for the slots (see Create characters).

2. At the right of the the Character line, click Create. The new character is added to the Tracking tree, with the populated slots as child nodes. Slots for which smart objects were selected are automatically named to match the character and slot (eg, Subject1_Head in the following example). The yellow warning icons indicate that some information is missing.

   

   Tip: After you have created a character, you can create multiple new characters based on the same configuration without having to use the Advanced properties. In the Tracking Setup panel, enter a new character name and click Create.

   

   You then assign objects to the empty fields as described in the next step.

3. Assign objects (these can be a single smart object, a composite smart object or a basic object) to the slots. To do this:

   1. Ensure the objects are positioned in the volume in a way that makes it easy to tell which one is which (you may want to place them on a person or mannequin).
   2. In the Tracking panel, select the relevant objects, and in the Properties pane, ensure that Auto Assign Enabled is cleared.
   3. In the 3D View, select an object andCtrl+select its slot in the Tracking tree, then right-click either the object or the slot and select Assign Object.
   4. In the same way, assign the remaining objects to the appropriate slots.

   In the Tracking tree, the slots now all have the correctly assigned objects, which are also displayed in the 3D View.

   

4. If you have set up characters or composite smart objects, but have not linked Pulsars to them (eg, if you created smart objects from the supplied templates for some or all of the slots in a new character), link the new smart objects to the correct devices. To do this:

   1. Select an object andCtrl+select the required smart object in the Tracking tree.
   2. Right-click either object and select Swap Cluster.

   3. If either of the smart objects is a composite smart object, from the sub-menu, select which device slot is to be affected by the swap.

      For more information, see Swap clusters.

When you have finished assigning objects, you can calibrate the character (see Calibrate characters).

To display or hide character slots and assigned objects in the Tracking tree, click the + or - symbol next to the character icon.

You can clear slots that you have assigned manually at any time after creation:

• To clear manual slot assignments, in the Tracking tree, right-click one or more character slots and then select Unassign object(s).

Calibrate characters

You must ensure each character is calibrated, but depending on the way in which you create your characters, the workflow is slightly different:

• If you use the automated workflow for object assignment and character calibration, both object assignment and calibration occur when you click Calibrate. Calibration assigns the clusters for which Auto Assign Enabled was selected to empty character slots; scales the source skeleton; and accounts for differences between the 'reference' position and where the clusters were actually placed on the participant, eg, if the participant was wearing heels, the clusters slipped, or the backpack straps were loose, etc (see About cluster calibration). Calibration also starts retargeting (if required).

• If you have used the manual workflow for object assignment and character calibration and have therefore manually assigned the clusters to the slots, calibration does not perform any further cluster assignment and just scales the source skeleton to the participant and accounts for differences between the reference position and actual cluster placement (see About cluster calibration). Calibration also starts retargeting (if required).

  To calibrate your characters, complete the following steps.

To calibrate characters:

1. Ensure each person to be calibrated is standingin the volume ina neutral pose (known as an N-pose), which is a relaxed pose with the hands by the sides.
2. In the Tracking panel tree, select the character(s) that are to be calibrated and right-click.

3. In the context menu, click Calibrate (or to calibrate all characters, press the shortcut Shift-C).

   (If the selected character is already calibrated, Recalibrate is displayed on the context menu. If you select this option, the existing calibration is overwritten.)

   

   Each character is calibrated and Evoke renders the character in the 3D View. You can set the View Filters to show either the character source (solving) view or the retargeting view. The scale value that Evoke calculates for each character is used by the Unreal or Unity Plugin to render the character at the correct size for each participant.

About cluster calibration

Cluster calibration corrects for minor variability in Pulsar placement on the feet and spine, along with refining the skeleton to give more lifelike character-solving. This helps adapt Characters From Clusters (CFC) to inconsistent application of the clusters to the body for specific objects on certain common axes. This happens automatically when you calibrate characters.

Example of a misaligned foot cluster: