Change appearance / sensitivity of the chaperone grid (OpenVR)

[notlion]

The Vive chaperone is pretty dang bright by default. Is it possible to control its sensitivity (motion required to activate) and overall brightness? Maybe we'd need to drop down to OpenVR via some getNative type interface?

[chaoticbob]

You can always drop into OpenVR (or Oculus) by doing something like this:

// Context
auto myCtx = dynamic_cast<ci::vr::openvr::Context*>( mVrContext );
// Get the OpenVR system object
::vr::IVRSystem *vrSystem = myCtx->getVrSystem();

// HMD
auto myHmd = dynamic_cast<ci::vr::openvr::Hmd*>( mHmd );