I am investigating the effects of reflectivity on the solar radiation reflected between two buildings. This is the model for my simulation.

By varying the reflectivity on the external walls on the two buildings, I am trying to find out how the radiation incident on different sections of the external walls vary. However, no matter how I vary the reflectivity of the external walls, the results are always the same. Is it a software limitation or can anyone help me with my problem?
Thanks in advance!

