2D map of the disk. The gray scale represents the values of the optical depth computed from the star to all points in the disk τ_★(r,z). The red lines represent the surface where τ_★(r,z) = 1. The green lines mark the location at which the total vertical optical depth at the mid-plane becomes lower than 10, 5, and 1. The solid blue line marks the altitude at which the optical depth in the z-direction toward the upper layers becomes 1. The line diverges to infinity beyond the line τ_υ = 1. All opacities are given at 1 µm.