FreeD In CHOP

Summary

The FreeD CHOP reads incoming camera tracking data sent over a network using the FreeD protocol and outputs CHOP channels that can be used to control a virtual 3D camera. FreeD is not exclusive to any particular tracking system, but is frequenty used as an interchange protocol since it is supported by a wide range of hardware and software. However, as an older standard, it is lower precision and does not contain len distortion data like Stype or Ncam, so it is recommended to use the hardware specific protocol when possible. Examples of hardware and software that support FreeD are Viz Virtual Studio and Panasonic PTZ cameras.

The channels exported by the FreeD CHOP are:

camera_id - a number from 0 - 255 that can be used to store an id number for the camera

tx, ty, tz - camera position, can be connected to the Camera COMP Translate parameters

rx, ry, rz - camera rotation, can be connected to the Camera COMP Rotate parameters

focus - a 24-bit positive integer (0-16 million) in arbitrary units that relates to the focus ring on a camera lens. Applications can interpret this value according to the hardware in use.

zoom - a 24-bit positive integer (0-16 million) in arbitrary units that relates to the zoom ring on a camera lens. Applications can interpret this value according to the hardware in use.

user - a 16-bit positive integer (0 - 65k) that can be used by the camera system to send custom user-defined data

Note: The FreeD CHOP only processes the 'D1' camera position and orientation message that is part of the FreeD protocol. All other message types will be ignored.

If the incoming network stream contains data for more than one camera, the Camera ID parameter can be used to select data from only one camera. If the Camera ID parameter is blank, then whatever data is received most recently will be shown - this could result in the data switching between cameras.

For more information or to diagnose connection problems, an Info CHOP can be connected to see if any packets have been dropped, skipped, or filtered out.

freedCHOP_Class

Parameters - FreeD Page

Active active - While On, the CHOP receives FreeD information sent to the network port. While Off, no updating occurs.

Protocol protocol - ⊞ - The network protocol to use. Refer to the Network Protocols article for more information.

• Messaging (UDP) msging -

• Multi-Cast Messaging (UDP) multicastmsging -

Network Address netaddress - When using Multicast, this is the address that FreeD will listen for packets on.

Network Port port - The port which FreeD will accept packets on.

Local Address localaddress - ⊞ - Specify an IP address to receive on, useful when the system has mulitple NICs (Network Interface Card) and you want to select which one to use.

• 192.168.1.10 192.168.1.10 -

• 127.0.0.1 127.0.0.1 -

Camera ID cameraid - This parameter can be used to select a specific camera when there are multiple streams of incoming data. To select the camera, the parameter value should match the incoming value in the camera_id channel. If the parameter is blank, no filter will be applied and the channels will display whatever camera data was received last.

Parameters - Common Page

Time Slice 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 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.

Export Method 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 geo1/transform1:tx.

Export Root autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is Path:Parameter are relative to.

Export Table exporttable - The DAT used to hold the export information when using the DAT Table Export Methods (See above).

Info CHOP Channels

Extra Information for the FreeD CHOP can be accessed via an Info CHOP.

Specific FreeD CHOP Info Channels

• valid_packets -

• unrecognized_packets -

• corrupt_packets -

Common CHOP Info Channels

• start - Start of the CHOP interval in samples.

• length - Number of samples in the CHOP.

• sample_rate - The samplerate of the channels in frames per second.

• num_channels - Number of channels in the CHOP.

• time_slice - 1 if CHOP is Time Slice enabled, 0 otherwise.

• export_sernum - A count of how often the export connections have been updated.

Common Operator Info Channels

• total_cooks - Number of times the operator has cooked since the process started.

• cook_time - Duration of the last cook in milliseconds.

• cook_frame - Frame number when this operator was last cooked relative to the component timeline.

• cook_abs_frame - Frame number when this operator was last cooked relative to the absolute time.

• cook_start_time - Time in milliseconds at which the operator started cooking in the frame it was cooked.

• cook_end_time - Time in milliseconds at which the operator finished cooking in the frame it was cooked.

• cooked_this_frame - 1 if operator was cooked this frame.

• warnings - Number of warnings in this operator if any.

• errors - Number of errors in this operator if any.

TouchDesigner Build: Latest\nmw-blank2023.112802021.10000before 2021.10000

An Operator Family which operate on Channels (a sequence of numbers (Samples)) which are used for animation, audio, mathematics, simulation, logic, UI construction, and data streamed from/to devices and protocols.

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 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. TOPs have Channel Mask, a similar feature.

samples-per-second of a CHOP. Each CHOP in your network has a sample rate. In contrast, the overall timeline has a Frame Rate, which is the number of frames to cook and display per second, generally your monitor display frequency, default 60.

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.

An Operator Family that manipulates text strings: multi-line text or tables. Multi-line text is often a python Script or GLSL Shader, but can be any multi-line text. Tables are rows and columns of cells, each containing a text string.

The location of an operator within the TouchDesigner environment, for example, /geo1/circle1, a node called circle1 in a component called geo1. The path / is called Root. This path is displayed at the top of every Pane, showing which Component's network you are currently in. To refer instead to a filesystem folder, directory, disk file or http: address, see Folder.

Every operator in TouchDesigner has a set of control Parameters that can be integer or floating point numbers, menus, binary toggles, text strings or operator paths, which determine the output of the operator.

TouchDesigner is a hierarchy of components. "root" is the top-most network in the hierarchy. The Network Path or Path for root is simply /. A typical path is /project1/moviein1.