Progressive escape probabilities, corresponding to the anisotropic case, are shown for two epochs, days 1000 and 1500, for the 3.6- and 8.0-µm Spitzer IRAC bands. The other two IRAC bands, 4.5 and 5.8 µm, also show a similar behavior. The escape probabilities are presented in the top panel as a function of ejecta velocities, while in the bottom panel, we show the probabilities as functions of the normalized He-core velocities (normalized with respect to the velocity of the outer edge of the He core in that direction). The escape probability in this scenario is dependent on the viewing angle; here we present the three axial directions. See Sect. 5.2 for more details.