Revert "Delete math.o"

This reverts commit 55cb8a375c9fec48a61d0f3c9dfd30cdc19a89e9.
Revert "Revert "Delete math.o""

This reverts commit 927b6fcfc2892bb53c0ce3d6b23e1b8fc89953ca.
Revert "Delete run.sh"

This reverts commit 5a9936438ac2caa4e1ebb527cb2623521018071e.
Makes the atmosphere scattering right, added a lot of comments.