I am developing an application that will use the Kinect v2 on Windows with OpenNI 2, but needs to be 32-bit because it also uses a different 32-bit library. I've installed the 32-bit version of OpenNI 2 but can't find a 32-bit version of the Kinect 2 SDK. Can you build a 32-bit application against Kinect 2 libraries?
Yes, you can. I built the OpenNI2-Kinectv2-driver, which uses the Kinect v2 SDK, as a 32-bit DLL and it works fine. So you can use the Kinectv2 SDK in your 32bit application.
But you will still need a 64bit system to run your 32bit application, because the Kinect v2 itself is not supported on 32bit systems.