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).
Parameters
Network
Direction
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).
Address
The address of the remote server.
Port
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.
Data Link
The portion of data to send over the link.
Current Frame Only
Sends the value of the current frame (1 sample per channel).
Current Time Slice
Sends the portion of the channel from the last cook time to the current cook time.
Full Channel
Sends all the data in all the channels.
Endian
Transmit either Little Endian format data (Intel) or Big Endian (MIPs, PowerPC).
Active
Data is only transmitted or received when this toggle is on.
Channel
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).
Buffer Size
The maximum number of samples that the receive buffer can hold (per channel).
Common
Some of these parameters may not be available on all CHOP nodes.
Scope
To determine which channels get affected, some CHOPs have a scope string. Patterns can be used in the scope, for example * (match all), and ? (match single character).
The following are examples of possible channel name matching options:
chan2
Matches a single channel name.
chan3 tx ty tz
Matches four channel names, separated by spaces.
chan*
Matches each channel that starts with chan.
*foot*
Matches each channel that has foot in it.
t?
The ? matches a single character. t? matches two-character channels starting with t.
r[xyz]
Matches channels rx, ry and rz.
blend[3-7:2]
Matches number ranges giving blend3, blend5, and blend7.
blend[2-3,5,13]
Matches channels blend2, blend3, blend5, blend13.
t[xyz]
[xyz]matches three characters, giving channels tx, ty and tz.
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 rate of first input to resample others.
Resample At Maximum Rate
Resample to highest sample rate.
Resample At Minimum Rate
Resample to the lowest sample rate.
Error if Rates Differ
Does not accept conflicting sample rates.
Units
The units for which time parameters are specified.
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).
Note
When you change the Units parameter, it does not convert the existing parameters to the new units.
Time Slice
Time Slicing is a feature which boosts cooking performance and reduces memory usage. Traditionally, CHOPs calculate the channel over its entire frame range. If the channel does need 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 known as a Time Slice.
Unload
Causes the memory consumed by a CHOP to be released after it is cooked and the data passed to the next CHOP.
Export Prefix
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 /obj/geo1/tx.
Note
You can leave the Export Prefix blank, but then your CHOP track names need to be absolute paths, such as obj:geo1:tx.
Graph Color
Every CHOP has this option. Each CHOP gets a default color assigned for display in the Graph port, but you can override the color in the Common page under 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.
| See also |
Pipe In
Pipe Out
