Note: Only available in TouchDesigner Pro.
The BlackTrax CHOP will provide motion tracking data from BlackTrax Motion Tracking Systems is a vision-based real-time tracking system developed by CAST Software that specializes in large-scale performances. BlackTrax Beacons ("BTBeacons") are attached to performers or rigid objects, and the BlackTrax system accurately tracks the Beacon's position, rotation, velocity, and acceleration.
The BlackTrax CHOP works in conjunction with the BlackTrax system. BlackTrax tracks up to 85 BlackTrax Beacons and sends data regarding their position, rotation, velocity, and acceleration to TouchDesigner inside RTTrPM Packets. Each Beacon can have up to 3 LEDs attached, which can also be independently tracked in TouchDesigner. Each Beacon will have an ID that is specified in BlackTrax software and that Beacon ID must be mapped correctly to CHOP channels in TouchDesigner using the Mapping Table. Alternatively if the IDs are incremental then the "From Max Beacons" option in "Output Format" can be used.
The server software should be set to send data in the WYSIWYG coordinate system (which should be the default). Rotations should be sent in Euler angles, not Quaternions. TouchDesigner should support both endian settings, but it's best to leave those as their default values.
Parameters - BlackTrax Page
active - While on, the CHOP receives information sent to the network port. While Off, no updating occurs.
port - The port that will accept packets.
protocol - ⊞ - The network protocol to use. Refer to the Network Protocols article for more information.
- Messaging (UDP)
- Multi-Cast Messaging (UDP)
netaddress - When using Multicast, this is the address that will listen for packets.
samplerate - Sets the sample rate of this CHOP.
outputformat - ⊞ - Specifies the format for the CHOP channels (ie. how many beacons to add). "From Mapping Table" adds one beacon to the CHOP for every row in the mapping table. "From Max Beacons" adds the number specified in the "Max Beacons" parameter.
- From Mapping Table
- From Max Beacons
maxbeacons - Specifies how many beacons to add to the CHOP. Used with the "From Max Beacons" output format.
centroid - When enabled, adds beacon translation and rotation channels.
velocity - When enabled, adds beacon velocity channels.
acceleration - When enabled, adds beacon acceleration channels.
leds - When enabled, adds position channels for each LED in the beacon.
reset - Clears any stored beacons and removes any stale data.
mappingtable - A DAT table that maps beacon IDs to CHOP channels (beacon0, beacon1, etc.). The first row will map to beacon0, second row to beacon1, etc. Beacon ID is a unique non-negative integer and is specified within BlackTrax applications.
Below is an example of a mapping table that is tracking 3 beacons with IDs 10, 11, and 12. In this example 10 is mapped to beacon0, 11 is mapped to beacon1, and 12 is mapped to beacon2.
Parameters - Common Page
timeslice - Turning this on forces the channels to be "Time Sliced". A Time Slice is the time between the last cook frame and the current cook frame.
scope - To determine which channels get affected, some CHOPs use a Scope string on the Common page.
Sample Rate Match
srselect - ⊞ - Handle cases where multiple input CHOPs' sample rates are different. When Resampling occurs, the curves are interpolated according to the Interpolation Method Option, or "Linear" if the Interpolate Options are not available.
- Resample At First Input's Rate
first- Use rate of first input to resample others.
- Resample At Maximum Rate
max- Resample to the highest sample rate.
- Resample At Minimum Rate
min- Resample to the lowest sample rate.
- Error If Rates Differ
err- Doesn't accept conflicting sample rates.
exportmethod - ⊞ - This will determine how to connect the CHOP channel to the parameter. Refer to the Export article for more information.
- DAT Table by Index
datindex- Uses the docked DAT table and references the channel via the index of the channel in the CHOP.
- DAT Table by Name
datname- Uses the docked DAT table and references the channel via the name of the channel in the CHOP.
- Channel Name is Path:Parameter
autoname- The channel is the full destination of where to export to, such has
autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is Path:Parameter are relative to.
exporttable - The DAT used to hold the export information when using the DAT Table Export Methods (See above).
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samples-per-second of a CHOP. Each CHOP in your network has a sample rate, whether it is used or not. The overall timeline has a "frame rate", which is the number of animation frames per second, generally your monitor display frequency.
To pulse a parameter is to send it a signal from a CHOP or python or a mouse click that causes a new action to occur immediately. A pulse from a CHOP is typically a 0 to 1 to 0 signal in a channel, and a pulse via python is via a
.pulse() call on a pulse-type parameter, such as Reset in a Speed CHOP.
A Time Slice is the time from the last cook frame to the current cook frame. In CHOPs it is the set of short channels that only contain the CHOP channels' samples between the last and the current cook frame.
A parameter in most CHOPs that restricts which channels of that CHOP will be affected. Normally all channels of a CHOP are affected by the operator.
Exporting is the connection of CHOP channels to parameters of operators. The output of each exporting CHOP is one or more channels, active only while the CHOP Viewer is on. The current value of a channel can be exported to a parameter of any operator, overriding that parameter's value. See Parameter.
Parameters in TouchDesigner are an operator's settings (numbers, menus, flags, strings, paths) which the user can alter. Parameters for any operator can be opened by right-clicking on the operator and selecting "Parameters..." A currently selected operator's parameters can be viewed in a Network Editor by pressing the keyboard shortcut 'p'.