Problem: radiation modelling with viewFactors

The radiation modelling with viewFactors produces different results in v1612+ compared to the older OpenFOAM versions and the Foundation releases. See the attached image of the chtMultiRegionSimpleFoam tutorial. Indeed the radiative heat transfer seems to be completely disabled in v1612+ (and v1606+).

Steps to reproduce: Run the tutorials/heatTransfer/chtMultiRegionSimpleFoam tutorial with v1612+ and 4.1 and check the temperatures and the Qr fields.