Left: sketch of the p-ray geometry. The quarter circle plotted in the bottom left represents the stellar surface and various p-rays leaving the system toward the observer (located to the right of the system) are indicated. The p-rays with values greater than 1 originate in the wind, which extends out to 120 stellar radii. Middle: sketch of the conversion from p-ray geometry to emergent intensity geometry. The quarter circle in the bottom left is the stellar surface and the shaded region represents the winds. For a given emergent angle, two p-rays are obtained, one originating from the stellar surface (p_s) and one originating in the wind (p_w) Right: sketch of emergent intensity geometry. A patch of the stellar surface is plotted with two emerging rays, one normal to the surface (labeled ) and one pointing to the observer (labeled I_λ). θ is the emergent angle of the ray toward the observer and a represents the area of the patch.