BlackTrax Overview
BlackTrax is a vision-based system that connects to different third-party applications, such as robotic lights, media servers, and any other third party that accepts the RTTrPM open protocol
BlackTrax Overview
BlackTrax (BT) is a vision based tracking system available from CAST, capable of tracking both objects and people. Tracking data from BT can be input into and mapped to objects or props within the Disguise visualiser.
The BT system uses an array of cameras placed on the stage rig to observe IR markers (small LEDs) placed on the talent or prop. These active markers generate rigid body information that is sent to Disguise as they are observed by an array of cameras mounted on the truss/staging. As long as the marker is observable by two cameras an accurate positional fix is possible.
The markers are attached to a small BT Beacon unit (usually attached to the talents belt). This unit provides power and control to the IR markers.
BlackTrax can integrate with Disguise in two ways:
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Actor/talent tracking
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Prop/screen tracking (used for movable scenic pieces)
A BlackTrax server contains the software programs required for configuring a BT system including BTwyg, BlackTrax, and Motive.
For additional information and training on using Blacktrax, please visit the CAST website
RTTrPM
BlackTrax RTTrPM Output Configuration
Applications like the BlackTrax real-time tracking system use RTTrPL and RTTrPM to interface with other lighting and third party applications (such as media servers, robotic cameras, and spatial audio systems) to provide tracking for automated lights, and projection mapping. With BlackTrax, RTTrPM is sent at a fixed rate of 100Hz.
BlackTrax RTTrpm
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BlackTrax sends out RTTrPM packets at a rate of 100Hz.
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BlackTrax by default sends out a heartbeat, or empty RTTrP header with an RTTrPM signature if no Beacon or LED data is available in the current frame.
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BlackTrax has the ability to add and remove different modules at any given time.
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In the BlackTrax implementation of the Trackable module with Timestamp, the Timestamp value is equal to the frame ID of the cameras in the BlackTrax system, as determined by the TimeKeeper.
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Euler Orientation modules always send with an order of
0x0123 (X1, Y1, Z1). -
The Tracked Point modules correspond to the LEDs on a BlackTrax Beacon (trackable), the Index is either
0x01,0x02or0x03. -
The context field in the RTTrP header is always set to the value of the current BlackTrax chapter (0x00000001, etc.), regardless if the current Trackable is present in the chapter, or if no Trackables are present in the RTTrPM packet (i.e. just the heartbeat is being sent). When in standby the Context field is set to 0xFFFFFFFF.
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The Zone Collision Detection module should only send Zone Sub-Modules that the Trackable is actively colliding (inside) with. If a Zone Sub-Module is not sent, it is assumed the collision is not happening and the Trackable is outside of the Zone.