Illustrating the angle dependence of ray-traced spectra. Ray-traced spectra in this article are computed from two inclination angles, θ = 5° (face-on observer) or θ = 85° (edge-on observer). From each of this inclination angles, photons are ray-traced backward to the accretion disk (blue lines). For one given inclination θ, photons reach the disk with a set of different directions because of light bending. This is illustrated in the figure by the fact that one given blue line is connected to a set of different directions of local emission in the disk (black arrows, the black vertical dashed line is the local normal). Directional ray-traced spectra are computed by transporting along each geodesic the specific intensity I_ν(r,i) emitted at the local position r in the direction i of this particular geodesic. Angle-averaged, ray-traced spectra are computed by transporting along each geodesic the angle-averaged specific intensity I_ν(r) obtained by averaging I_ν(r,i) over all emission angles i.