been working at this off and on for a few years the Dark Sun is a setting for Dungeons & Dragons, a world where the forces of evil, won. It's more John Carter's Barsoom, Dune, Conan and Clark Ashton Smith than Lord of the RIngs. a desert world baking under a dark red giant sun, where ancient sorceror-kings, despots, rule unchallenged in lands slowly turning to wasteland, and metals are incredibly scarce. Awesome concept, and cause of fans like me who've supported it for 2 decades, it's coming back to D&D, woot! :)

but what made it great to me was the art and ideas. Like "Spelljammer" (D&D in space), they had some of the greatest artists and concept folk around, and the ideas it inspired strongly appealed ot me, but since  Ic an't paint worth a damn, lol, I had to wait until 3D gprahics let me create such.

Brom was the guy who did mostof the Dark SUn art
http://web.tiscalinet.it/ffantasy/brom.htm
http://members.cox.net/dragons_sanctum/BromArt.htm
"Belgoi Enchanter" is about my all time fave piece of art, alas no where on the net I cna find has a high quality pic of "Verdant Passage"
http://members.cox.net/dragons_sanctum/Part1.jpg
the actual painting is PHENOMENALLY good.

What's this have to do with Vue?
Well, try creating the Dark Sun...
it's a Sun with a mostly dark crust shot through with crrackes and flames.
Spectral suns are just light sources with lens flares, not actual 3D objects.
It has ot be a 3D object cause it's so damn big (as red giants are) you can see it's a sphere.

But, Suns can't shine through a sphere...unless you turn Cast Shadows off (I'd forgotten that I'd solved that on earlier attmept, lol but thanks to fella who pointed that out)
So, now you cna put the sphere for the Sun, made very large and put up high, in front of the Sun.
You need the Sun object far off so it's beyond the atmosphere, and thus looks right.

I had to work out a complex (for me, lol) material to blend the edges of the sphere into the corona of the spectral sun, makingit appear that the 3D sun sphere bled intot he chromasphere that surrounds stars, and thus wouldn't have a fake looking hard edge, used angle of incidence to drive transprency.

to get it over all to look right I had to give the sphere overall transprency of about 43%, letting the spectral sun partially shine through. I blended the Angle of Incidence transprency to an altered version of the crack function so thecracks would shine more by letting through more light.
some glow driven by the transparency function helped too, making the hotter cracks and edge of sphere glow more

A layer baove the main surface of the SUn used fractal transparency with a reddish colour, to give a tinge of red to the sphere.

all this cause i't shard to get a Sun sphere, to blend in right with a Spectral sun and look ok.

this is the end result ;)

note though that spectral suns near horizon arne't speherical, or so it seems, so for prefection I'd need to scale the height of the sphere to be a bit less to let bottom of it blend more into the corona

I'll try and do a tutorial and freebie of the Sun for ya :)