Abstract: Various methods and systems are provided for authoring and presenting 3D presentations. Generally, an augmented or virtual reality device for each author, presenter and audience member includes 3D presentation software. During authoring mode, one or more authors can use 3D and/or 2D interfaces to generate a 3D presentation that choreographs behaviors of 3D assets into scenes and beats. During presentation mode, the 3D presentation is loaded in each user device, and 3D images of the 3D assets and corresponding asset behaviors are rendered among the user devices in a coordinated manner. As such, one or more presenters can navigate the scenes and beats of the 3D presentation to deliver the 3D presentation to one or more audience members wearing augmented reality headsets.

Abstract: The invention relates to a resonant cavity device such as a magnetron oscillator which is tunable by means of a tuning plunger associated with sealing bellows. A volume defined at least in part by the bellows and producing a range of spurious responses as the tuning plunger is moved is isolated from the resonant cavity or cavities of the device by an isolating choke. The choke may take the form of an annulus having a major radius of 1/4 .lambda. (where .lambda. is the mid-frequency of the tuning range) attached either to the plunger or to the main body of the device and between the bellows and the resonant cavity or cavities.