|Posted: 2010-August-31 at 3:30pm | IP Logged
It absolutely happens, i would bet that it depends on the thickness of the rings, size of particles, proximity to the lightsource, and a lot of other variables...so there is a fair amount of artistic license you can use since these details are up to you. One thing i do know is that no nebula is going to cast a shadow on a planet, they are just too dim. In fact if you were sitting in the middle of a nebula, they are so dim, you wouldn't even see it. And if a star is close enough to cause shadows, it's not going to be part of a constellation, it would be that planet's sun, outshining everything else. A binary or multiple system would be possible though, thats when you could get some interesting effects, in this one
i used 3 suns to cast shadows on the rings (planet's shadow on rings, but same idea...and yes the 2 dimmer shadows are rather hard to see) What happens, more or less, is that they cancel each other out to some extent, depending on brighness, proximity, etc.
If you were making it in PS you could try copying your rings layer. Use levels, color overlay, or whatever else you wish to make the rings black, then use the perspective transform tool to shape your rings to where the shadows should be (this is not an exact science, you have to basically guess) then control+select the planet layer so you have the planet's outline selected. Inverse select, and then erase the parts of the shadow that are out in space, and now you have 1 shadow. If you want mutliple shadows try copying that layer, moving it up or down to correspond to where the secondary light is coming from, and changing the opacity to something lower (since it's not pure shadow, its lit by the secondary suns)