This tutorial demonstrates how to use multitouch data in TouchDesigner. It shows how to use two different multitouch input devices: iPhone/iPad using an app called TC-Data, and Wacom tablets using software I developed called Tablet to OSC. I walk through accessing the data from both of these devices in TouchDesigner, modifying the data, and using it in an instancing setup.
You can download a couple related files from my gumroad (see asset links). One is the TouchDesigner and TC-Data project files, which you can get for free. Another is the Windows app called Tablet to OSC, which sends Wacom pen and multitouch data over OSC. This tablet data can be used for a wide variety of purposes.