Primitives Tracking

This step-by-step guide will help you implement a basic configuration of Primitives tracking based on the example of a pair of Copernics worn by performers or installed on props.

Before starting, make sure you do all manipulation on a controller Photon Server or ALBION.

Tracking: Rigid Body

  1. Open the I/O Manager module bry pressing [Alt+I].

  2. Click on the Albion tab.

  3. Create a new Virtual ID (1.) set at equidistance, in the center, of your two trackers. For that, indicate your two trackers IDs (2.) and set your virtual tracker ID (3.).

Make sure the ID you are choosing for your virtual tracker is not already used by other trackers, real or virtual.

  1. Open the 3D Scene module by pressing [Alt+C] or by selecting {System > 3D Scene} from PHOTON’s Main menu.

  2. Create a new Primitive that will be used as your Projection Surface. For example, in this case, we want to project a video under the performer that will follow him as he moves. Select {Primitives > Default object > Circle} to create a new circle Primitive which will act as the Projection Surface.

  3. Find the new Primitive in the 3D Scene Primitives list and rename it. Double click on its corresponding entry (it should by default be anmed “Circle”) in the Primitives list and enter a new name in the text field.

  1. Select the renamed Primitive by clicking on its entry in the Primitives list and open the Transform panel by pressing [T].

  2. Input the value 90 in the Rotate X slider in the Transform panel. The renamed Primitive should now be parallel to the 3D Scene Preview grid.

  1. Set the 3D Scene in the Operation mode by clicking on the [Operation] button or by pressing [3]. The UI should turn to blue.

  2. While your renamed Primitive is still selected, double click on the red dot (1.) in the center of the circle to declare a Rigid Point. This point will be used as reference to follow your tracker.

  3. While your renamed Primitive is still selected, click on the Settings button (2.) and match the Copernic ID with the number that was attributed to the Virtual ID (3.).

  4. While your renamed Primitive is still selected, open the Automation panel by pressing [A].

  5. Make sure the {Rigid Body} option is selected from the Albion Options dropdown menu and the [Auto Fade] toggle is disabled (4.) to avoid your object to fade out by itself. Enable the [Active] toggle (5.) to enable tracking.

  1. Now if the performer is wearing Copernics on his shoulders, the circle will be floating at the same height. We now need to update the Rigid Point position so the circle should be underneath his feet.

  2. While your renamed Primitive is still selected, ask the performer to stay as static as possible and disable tracking (disable [Active] toggle) (1.)

  3. While your renamed Primitive is still selected, press [V] to access the Translate manipulator and move the blue Y axis down to the floor (use MAJ + Mouse drag for more accuracy (2.). When you’re done, press (S) to exit Translate manipulator and take back control over the camera.

  4. While your renamed Primitive is still selected, in the Settings panel, click on the [update Rigid Points] button (3.) and then re-enable tracking (by clicking on the [Active] toggle) (4.).

  5. The performer can now move again and the circle will follow him sitting at his feet.The final steps will give you the ability to display content and choose which projectors to use to display the image.

  1. Switch the 3D Scene module to the Calibration mode. (1.)

  2. Select all the Displays (video projectors, in this case) you want to use to project content beneath the performer from the Calibration Tool Window list. (2.)

  3. Select the renamed Primitive from the drop-down menu underneath object visibility in the Calibration Tools Window and click the [add] button. The renamed Primitive should now be visible for each of the selected Displays (3.).

  1. Open the Timeline module by pressing [Alt+T].

  2. Select the Screen corresponding to your Primitive on the Timeline (1.) and add a new layer by clicking the [+] button on the layers option (2.). You can now drop Media Clips (or any other kind of Clips) on it (3.).

Tracking: Rotation and Translation using 4 Copernics

If you have to track the position and the orientation of a Projection Surface, you will need multiple Rigid Points. For example, a table used as a prop has to be tracked. A minimum of 4 Copernics placed on the tables corners are required for such a scenario.

  1. Create a new Primitive that will be used as your Projection Surface. For example, in this case, we want to project on the table as it moves. Open the 3D Scene module by pressing [Alt+C] and create a plane (the table’s surface) by selecting {Primitives > Default Object > Plane} (1.).

  2. Select the newly created plane by clicking on its entry in the 3D Scene Primitive list. (The plane can be renamed by double-clicking on its entry and typing a new name in the text field.)

  3. Open the Transform panel by pressing [T] (2.).

  4. Measure the table (in meters) and input the resulting values in the X and Y scale sliders located in the Transform panel (3.).

  1. Switch the 3D Scene module’s mode to Operation by pressing [3]. While the plane is still selected (1.), double-click on the 4 red dots sitting in each corners in order of your plane to declare Rigid Points (2.). Those points will be use as references to be followed by trackers.

  2. While the plane is still selected, open the Automation panel by pressing [A]. Make sure the {Rigid Body} option is selected (3.) from the Albion Options dropdown menu and the [Auto Fade] toggle is disabled to avoid your object to fade out by itself. All translation needs to be enabled and rotation set as All Axis (4.).

  3. Open the Settings panel by clicking on the [gearbox] button. Match the Copernic IDs to each of the four Rigid Points declared previously (5.). Obviously, the Copernics distribution must match the Rigid Points distribution. (top left corner with top left corner, bottom left corner with bottom left corner, etc.)

  4. Enable tracking by clicking the [Active] toggle (6.).

The final steps will give you the ability to display content on the table and choose which projectors to use to display the image.

  1. The final steps will give you the ability to display content on the table and choose which projectors to use to display the image.

  2. Open the Timeline module by pressing [Alt+T].

  3. Select the Screen that corresponds to the plane in the Timeline by clicking on its entry and click the [+] button to add a new layer.You can now drop Media Clips (or any other kind of Clips) on it.

  4. Go to calibration mode and in the calibration window select all projectors you want to use to display your pictures [ MAJ + click for multiple selection ].

  5. Open the 3D Scene by pressing [Alt+C].

  6. Switch the 3D Scene module to the Calibration mode by pressing [4]. Select all the Displays (video projectors, in this case) you want to use to project content on the table from the Calibration Tool Window list.

  7. Select the plane from the drop-down menu underneath object visibility in the Calibration Tools Window and click the [add] button. The plane 0

The projection will now be mapped on your table and follow the movement in all directions.

Extra: Object Visibility

  1. Select the plane in the 3D Scene Primitives list and access the Properties panel by pressing [p].

  2. In the blending option menu, enable “Alpha from Sequence” to derive Alpha from the compositing of your screen.

Now if your content contains any alpha content the plane itself will become see-thru and give you the ability to see content displayed under it instead of black areas.