With Spectacles 3 enabled, you are able to occlude your scene based on the depth information in the Spectacles video. To do this, in the Objects panel, press Add New, and select Depth Setter.
Additionally, you can add a material that represents the depth map of the Spectacles 3 video. To do this, in the Resources panel, press Add new > Spectacles Depth. In script, this material allows you to access the distance value of a screen coordinate in the video on a frame using the getDepth API. Take a look at the Depth template for an example of how to use this.
Finally, since the Lens runs after the video has been captured, you are able to get the path that the device travels during the video. To use this, in a script, use the getDevicePath and getDevicePathIndex API found in the Device Tracking component. Take a look at the Path template for an example of how to use this.