Tracking Tips and Tricks for Multiple PS Eye Cameras

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Tracking Tips and Tricks for Multiple PS Eye Cameras

Light Settings

Colors differ due to non-ambient lighting

Ideally, lighting should be ambient. In this case colors of clothes and body will look the same in all cameras, and you can leave default light settings.

But in real-life you can have non-uniform lighting, when most light comes from window, or bright light source. In this case colors will be darker in cameras directed towards this light source, and lighter in the rest of cameras. In such situation adjusting light settings may substantially improve tracking.

You can find light settings at Scene tab.

  • Light source position is marked by yellow ball (1). Click and drag light control to orbit the light source (2). Approximate postions will be fine, you do not need to be very accurate.
  • You can also change light intensity (3). You can check how it influences tracking using View > Pose Mismatch window (4).

Ground Height Fine-Tuning

Sometimes ground height detected during calibration may differ from the actual. This depends on particular flashlight you use for calibration, lighting conditions and other circumstances. Incorrect ground height may cause problems in feet tracking. Ground Height Fine-Tuning setting allows you to manually correct the ground height.

  • To make sure that the ground height is correct, you need to check if feet stand on the ground surface.
  • Run Refit Pose for T-pose frame and zoom / rotate the viewport to see the feet position clearly
    • If you see that feet are above the ground, detected ground is lower than actual
    • If you see that legs are bent a little, this may mean that detected ground is higher than actual
Tip: Legs bending may also be caused by incorrect height of actor. To check if ground height is correct, turn off Enable ground collisions on Scene tab, and run Refit Pose. If you see that feet are below the ground, detected ground is higher than actual.
  • Use Ground Height Fine-Tuning slider at Scene tab to change the ground height, and re-run Refit Pose to check the updated ground position.
Ground is below actual
Ground is above actual

Using Pose Mismatch View

Pose Mismatch window is a very useful tool which allows you to understand how scene and actor settings affect tracking.

  • Pose Mismatch window is shown using View > Pose Mismatch menu item
  • Mismatch number at the top evaluates how actor model matches to video in the current frame
  • You need to run Refit Pose to match actor model to video before comparing Mismatch numbers
  • Lower value of Mismatch number means better match. So your need to minimize Mismatch number while choosing settings
Note: When Mismatch number is negative, then greater absolute value means better match.
Tip: In the Pose Mismatch window good match is marked with green, bad match is marked with red. This information is especially useful when changing actor model dimensions, as you can see which parts of the body have matching problems.
Pose Mimatch View

Checking Camera Calibration

Actor model shifted from actor image

Frequent cause of tracking errors is incorrect camera calibration, that can be result of moving camera(s) after calibration recording. You can use T-pose to detect this problem:

  • Run Refit Pose for T-pose after adjusting actor and scene settings
  • Make sure that actor model is well aligned with video in all cameras
  • If any camera was shifted, you should see the shift of the actor model relative to the actor's image on video (see the screenshot)
Tip: We recommend to run calibration twice - before and after capture session. If any camera was moved during capture session, calibration made after the session can give you correct camera positions.