We study the spatialization of the sound field in a room, in particular the evolution of room impulse responses as function of their spatial positions. The presented technique allows us to completely characterize the sound field in any arbitrary location if the sound field is known in a certain finite number of positions. In this paper, we include an analytical solution of the problem for any rectangular room. Further results on reconstruction of the sound field by interpolation of the Plenacoustic function are discussed.