For a lens flare, this is quite good:
[Lens flare postprocess filter)
If you are looking for godrays theres volumetric lights detailed here (although I havent tried it):
panda3d.org/manual/index.ph … ge_Filters
For night / day cycles, I was thinking the easiest idea would be to create a linear gradient in photoshop. Each clocktick you’d sample the image (using PNMImage) depending on how far you are into the day, and apply that to your lights. (Sort of like tonemapping).