This CHOP is similar to the Pipe In/Out CHOPs in Network mode. It provides a fast, asynchronous connection between two remote Houdini processes. The CHOP operates in either Transmit or Receive mode.
A connection is establish between a client Network CHOP and a server Network CHOP. By default, the Transmitting Network CHOP is the server; however, if the parameter “Default Client/Server Setup” is off, the Receiving Network CHOP becomes the server. Both the Transmitting and Receiving CHOPs must choose the same client/server setup. This option is mainly for interfacing with external applications; if you are transmitting from Houdini to Houdini, you do not need to change this parameter.
The server Network CHOP (normally the Transmitter) selects a port number between 5000 and 10000. The client Network CHOP (the receiver) then connects to the server by setting the address to the server hostname, and the port to the same port as the server Network CHOP.
The Transmitting Network CHOP requires an input to transmit. Transmission occurs whenever the input changes, or if in Current Frame or Time Slice mode, whenever the playbar moves. The Network CHOP can choose a Data Link mode to send the current frame only (for low bandwidth situations), the current time slice (for realtime applications) or the full channel. Both the Transmitting and Receiving CHOPs should use the same “Data Link” mode.
The Receiving Network CHOP receives all of the data from the Transmitter. However, if the CHOP is not actively reading the data (by cooking) it will pile up in the buffer. By default, the maximum buffer size is 1000 samples per channel (the limit can be disabled).
Transmit or Receive data. When transmitting, an input is required.
Default Client/Server Setup
When on, the Transmitting CHOP is the server; when off, it is the client (see above).
The address of the remote server.
The port to use (between 5000 and 10000). You can have multiple parallel connections as long as the port numbers are distinct. A transmitter/receiver pair must use the same port.
Transmit either Little Endian format data (Intel) or Big Endian (MIPs, PowerPC).
Data is only transmitted or received when this toggle is on.
Send Channel Names
Sends the channel names as well as the data if on.
Receive Most Recent Data
Uses the most recently sent data. If the buffer contains 10 samples and 4 are required, the most recent 4 are used and the previous 6 are lost.
Limit Input Buffer Size
Places a limitation on the size of the receive buffer (defined by the next parameter).
The maximum number of samples that the receive buffer can hold (per channel).
Some of these parameters may not be available on all CHOP nodes.
To determine the channels that are affected, some CHOPs have a scope string. Patterns can be used in Scope, for example
* (match all), and
? (match single character).
The following are examples of possible channel name matching options:
Matches a single channel name.
chan3 tx ty tz
Matches four channel names, separated by spaces.
Matches each channel that starts with
Matches each channel that has
foot in it.
? matches a single character.
t? matches two-character channels starting with t.
Matches number ranges, giving
[xyz]matches three characters, giving channels
Sample Rate Match
The Sample Rate Match options handle cases where multiple input CHOPs’ sample rates are different.
Resample At First Input’s Rate
Use the rate of the first input to resample the others.
Resample At Maximum Rate
Resample to the highest sample rate.
Resample At Minimum Rate
Resample to the lowest sample rate.
Error if Rates Differ
Does not accept conflicting sample rates.
The units of the time parameters.
For example, you can specify the amount of time a lag should last for in seconds (default), frames (at the Houdini FPS), or samples (in the CHOP’s sample rate).
When you change the Units parameter, the existing parameters are not converted to the new units.
Time slicing is a feature that boosts cooking performance and reduces memory usage. Traditionally, CHOPs calculate the channel over its entire frame range. If the channel needs to be evaluated every frame, then cooking the entire range of the channel is unnecessary. It is more efficient to calculate only the fraction of the channel that is needed. This fraction is the Time Slice.
Causes the memory consumed by a CHOP to be released after it is cooked, and the data passed to the next CHOP.
The Export Prefix is prepended to CHOP channel names to determine where to export to.
For example, if the CHOP channel was named
geo1:tx, and the prefix was
/obj, the channel would be exported to
You can leave the Export Prefix blank, but then your CHOP track names need to be absolute paths, such as
Every CHOP has this option. Each CHOP gets a default color assigned to it for display in the graph, but you can override the color with the Graph Color. There are 36 RGB color combinations in the palette.
Graph Color Step
When the graph displays the animation curves, and a CHOP has two or more channels, this defines the difference in color from one channel to the next, giving a rainbow spectrum of colors.