The Audio Panel sets the audio volume, and lets you choose which CHOP provides the audio waveform data for the animation timeline for lip syncing. You can access the Audio Panel it by selecting it from the Windows drop-down menu or by pressing Alt + I.
Note
This panel controls the audio that Houdini provides to the operating system. The operating system may do further processing or volume adjustment to the data before sending it to the speakers.
Audio output controls
Off
Do not play audio.
Scrub
Audio plays when during playback and when you scrub on the timeline.
You might want to disable 'Playback/Integer Frame Values' in the 'Global Animation Options'.
Audio scrubbing is more precise when the scrubbing can change time in small steps.
The options below the Timeline radio button control how audio plays when you scrub along the timeline.
Repeat
When you hold the play head still while scrubbing, the audio will repeat around that frame.
Sustain
Controls the length of audio played when repeating. Higher numbers give shorter bursts of audio. (30 means 1/30th of a second, 45 means 1/45th of a second).
Rate
Controls the length of audio played around each frame you scrub to. Higher numbers give shorter bursts of audio (30 means 1/30th of a second, 45 means 1/45th of a second).
Realtime
Plays a CHOP whose Time Slice option is on (forwards only).
Audio Output Delay
The delay applied to the audio output.
Test
Lets you play audio independent of the audio timeline.
VCR Controls
These buttons are similar to the ones on the playbar. See playbar help for more information.
On Change Rewind
Restarts the audio when a change is made.
Mono
Output audio on only one channel.
Tie
Lock the volumes of the left and right channels together (changing one changes the other). When this option is off, you can set the volumes of the left and right audio channels independently.
Meter
Turns on the live-updating VU meter.
VU Meter
Displays the current volume of CHOPs audio output. The green area represents output between -1 and +1. The red zone represents output outside -1 to +1, indicating the waveform is being clipped.
L and R
Control the volume of the left and right audio channels. When the Tie checkbox is on, these sliders are locked together.
CHOP
Get the audio output from a channel operator (CHOP). Click the + icon to choose the CHOP from your network hierarchy.
File
Get the audio output from a sound file. Click the + icon to choose the file.
Audio Second … is at Frame
When the audio source is File, you can use these options to sync the sound file to your animation. To start the output later in the sound file, increase the Audio Second option. To start the output later in the animation, increase the is at Frame option.
Tip
You can also use the audiopanel HScript command to control audio output.