Examples of dark patches forming in models with different stellar parameters. Shown are bolometric intensity maps of the models in Table 1. Top row (AGB stars): st28gm06n051 (M_⋆ = 1 M_⊙, T_eff ≈ 2907 K), st28gm06n056 (M_⋆ = 1 M_⊙, T_eff ≈ 2848 K; opposite side of model shown in Fig. 13), st28gm05n032 (M_⋆ = 1.5 M_⊙, T_eff ≈ 3149 K). Bottom row (RSG stars): st35gm04n045 (M_⋆ = 5 M_⊙, T_eff ≈ 3368 K; different snapshot of our standard model shown in Fig. 2), st35gm04n048 (M_⋆ = 5 M_⊙, T_eff ≈ 3288 K; opposite side of model shown in Fig. 10), st34gm02n002 (M_⋆ = 8 M_⊙, T_eff ≈ 3359 K).