Being able to change and adjust your various tempi on the fly is crucial for many live oriented projects. While there is an easily accessible Tap Tempo & Listen button in the Beat Dialog, many performers would rather have a hardware or external option. In TouchDesigner you can quickly create a few Scripts to replicate the Tap Tempo and Listen button, allowing you to adjust your desired Time COMP from any hardware or external software.
opparm /path/to/time tempo `execute("beat -t")`
1) /path/to/time is the path to the Time COMP you want to change
2) Those are back-ticks around the expression, NOT single quotations (use the tilde key)!
Proceed to create another DAT and enter the following command:
beat -b $BPM
The function of this Script is to reset the tempo averaging calculations. For instance, if you tap in a tempo using the first Script, then go to tap in another after a minute, your tempo would drop significantly when you went to tap in the new tempo, as the passing minute of inactivity has been added to the tap tempo averaging calculations. The second Script is similar to activating the Listen button in the Beat Dialog, except that it should be triggered after you're finished tapping in a tempo or before you start tapping in a new tempo (either works).
Start by opening the TapTempoExample.toe (link above) and opening the Beat Dialog.
The Scripts in this project are being run inside of CHOP Execute DATs and are controlling the main Time COMP (found in /local). As you click with your mouse on the Tap Tempo momentary button, you will see the tempo in the Beat Dialog changing.
If you wanted to map your specific hardware or software to the Scripts, you would simply add an OSC In CHOP or MIDI In CHOP, and then connect its output to the Null CHOP or the TUIK buttons in the example project file.
TOuch Environment file, the file type used by TouchDesigner to save your project.
TouchDesigner User Interface Kit - A collection of User Interface components.