Spherical Stabilizer Node

VR live action often uses handheld cameras, causing shaky footage to be a common problem. The Spherical Stabilizer node automatically identifies and tracks visible features in the footage, and then analyzes their movement to identify pan, tilt, and roll rotations. After tracking, it is then possible to smooth out or stabilize the rotation of the footage.

Spherical Stabilizer Node Inputs

The Spherical Stabilizer node has a single orange input.

• Image: This orange image input node requires an image in a spherical layout, which can be any of Lat Long (2:1 equirectangular), Horizontal/Vertical Cross, or Horizontal/Vertical Strip.

Spherical Stabilizer Node Setup

In the example below, a 2:1 Lat Long image is connected to the input of the Spherical Stabilizer node. Once the image is stabilized, the output of the Spherical Stabilizer node is a steadied clip.

Spherical Stabilizer Node Controls Tab

The Controls tab contains parameters to initiate the tracking and modify the results for stabilization or smoothing.

Reject Dominant Motion Outliers While Tracking
With this control activated (the default setting), features that move contrary to the majority of other features are ignored. This helps ignore the movement of subjects in the shot, preferring stable and consistent markers from the surrounding environment.

Track Controls
These buttons initiate tracking and analysis of the shot. Be aware that the reference frame used for stabilization is set to the first frame tracked.

• Track Backward from End Frame starts tracking backward from the end of the current render range.
• Track Backward from Current Time starts tracking backward from the current frame.
• Stop ceases tracking, preserving all results so far.
• Track Forward from Current Time starts tracking forward from the start of the current render range.
• Track Forward from Start Frame starts tracking forward from the current time.

Append to Track

• Replace causes the Track Controls to discard any previous tracking results and replace them with the newly-created track.
• Append adds the new tracking results to any earlier tracks.

Stabilization Strength
This control varies the amount of smoothing or stabilization applied, from 0.0 (no change) to 1.0 (maximum).

Smoothing
The Spherical Stabilizer node can eliminate all rotation from a shot, fixing the forward viewpoint (Still mode, 0.0) or gently smooth out any panning, rolling, or tilting to increase viewer comfort (Smooth mode, 1.0). This slider allows either option or anything in between.

Offset Rotation
Often a shot is not entirely level and needs the horizon to be realigned, or perhaps a desired pan should be reintroduced after fully stabilizing the shot. The Offset Rotation controls allow additional manual control of the Spherical Stabilizer’s rotation of the footage, for pitch/tilt (X), pan/yaw (Y), and roll (Z), respectively. Rotation is always performed in the order X, Y, Z.

Spherical Stabilizer Node Settings Tab

The Settings tab in the Inspector is duplicated in other VR nodes. These common controls are described HERE.