I have a vaulted ceiling in my family room and I want to install crown molding. The room has a beam that spans the length of the ceiling along the apex. I was able to find out how to make the transition at the corner where the ceiling begins to rise but I can't visualize how to miter the corner at the apex where the wall meets the beam. I want to run the molding along the beam which cuts the ceiling into two separate sections if you will. Can anyone help?