Example of the four steps of the patch model computation for an overcontact system. Top left: mesh representing the geometry of the system. Top right: same mesh, but with the face color representing the local temperature of each mesh element. Lighter shades represent higher temperatures and darker shades represent lower temperatures. Bottom left: same as top right, but with assigned spectral profiles plotted for three triangles across the surface. The He I λ4471 and He II λ4541 lines are plotted. Bottom right: final integrated spectral line profiles for the entire visible surface for the orientation shown in the other panels of this figure. Again, the He I λ4471 and He II λ4541 lines are plotted.