This CHOP listens for gamepad or joystick input, including all of the selected device’s buttons, axes, trackballs and POVhats, and outputs channel data.
The range of axis values is scaled to -1 to 1 (originally -32768 to 32767). 0 means the axis is placed at center.
For buttons, the chop output 1 when pressed, 0 when released.
For trackballs, the chop outputs dx and dy, denoting deltas in x and y position. HOWEVER, this part is NOT tested NOR scaled, due to lack of access to such device.
For POVhats, the chop outputs its direction which is comprised of up to 2 of the following 4 directions: up, down, left, right. It can also be centered.
The Gamepad and DeviceTransform CHOPs can be used together to drive objects (like the camera object) in a “First-Person” way.
This CHOP provides two interaction modes: 1. The gamepad mode requires the connected device to be a gamepad,
2. The joystick mode should support generic joysticks, including gamepads.
Gamepad mode supports game controllers such as PS or Xbox gamepads. Joystick mode supports general joysticks.
Select the desired input device from the dropdown of this parameter.
Specify the deadzone by percentage of the max value. For example, 0.2 means all inputs below 20% of the max possible input will be ignored.
This parameter should NOT be used regularly. Install the corresponding driver for the controller instead.
Left Stick X Axis
Specify the output channel name of values from left stick X axis.
Left Stick Y Axis
Specify the output channel name of values from left stick Y axis.
Right Stick X Axis
Specify the output channel name of values from right stick X axis.
Right Stick Y Axis
Specify the output channel name of values from right stick Y axis.
Left Trigger (L2)
Specify the output channel name of values from left trigger (LT/L2).
Right Trigger (R2)
Specify the output channel name of values from right trigger (RT/R2).
Left Bumper (L1)
Specify the output channel name of left bumper (LB/L1) button state.
Right Bumper (R1)
Specify the output channel name of right bumper (RB/R1) button state.
Left Stick Down
Specify the output channel name of whether left stick is pressed.
Right Stick Down
Specify the output channel name of whether right stick is pressed.
From the dropdown, select the desired axes to output from a list of available axes provided by the joystick with generic names, i.e. axis1, axis2…
From the dropdown, select the desired trackballs to output from a list of available trackballs provided by the joystick with generic names, i.e. ball1, ball2…
The output will be in the form: “ball1-dx”, “ball1-dy”…
Joystick POV Hats
From the dropdown, select the desired POV hats to output from a list of available POV hats provided by the joystick with generic names, i.e. hat1, hat2…
If the device is a gamepad then there will be one hat available, which is the essentially the direction pads. The output will be in the form: “hat1-up”, “hat1-down”, “hat1-left”, “hat1-right”…
The alignment option to use.
Extend to Min/Max
Find the earliest start and latest end, and extend all inputs to that range using the extend conditions.
Stretch to Min/Max
Find the earliest start and latest end, and stretch every channel’s start and end to that range.
Shift to Minimum
Find the earliest start and shift all channels so they all start at that index. All channels are extended to the length of the longest one.
Shift to Maximum
Find the latest end and shift all channels so they all end at that index. Extend all channels to the length of the longest one.
Shift to First Interval
Shift all channels to the start of the first channel and sample all inputs using the first input’s range.
Trim to First Interval
Trim all channels to first channel’s range.
Stretch to First Interval
Stretch all channels to the first channel’s range.
Trim to Smallest Interval
Trim all channels to the smallest start/end interval. The start and end values may not come from the same channel.
Stretch to Smallest Interval
Stretch all channels to the smallest start/end interval. The start and end values may not come from the same channel.
Specifies the range of data to generate.
Use Full Animation Range
All of the animated range.
Use Current Frame
Only the sample at the current frame.
The range is specified from the Start and End parameters.
Use Value Animation
The range is taken from range of keys available in the evaluated Value parameters.
The start time of the channel range.
The end time of the channel range.
The sample rate of the CHOP.
Number of Threads
The number of separate threads to use to evaluate the channel samples. The default is no threading.
Since Houdini evaluates the VEX program for each sample in the input geometry, it can benefit greatly from threading on a multi-processor or multi-core machine when the CHOP nodes have many samples.
Some of these parameters may not be available on all CHOP nodes.
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:
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 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.
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).
When you change the Units parameter, it does not convert the existing parameters to the new units.
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.
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 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.