If we would want realistic gas cloud, it should be rendered only to a background image as the density is just too low to be seen in small distances.
That would also look very boring and wouldn't fit the game as we already had nice and chunky nebula with storms and all.
High/low density variation would be very nice addition as one cound fly trough formations during dogfights or reveal enemy capship coming trough a denser area.
Something like artist controlled density field would be sweet especially with proper lighting. (multi scattering from sun and single scattering for local lights and glowmaps.)
I could foresee something added into FRED similar to the asteroid field system, however it would control nebular density within certain regions, and it would operate on sphere system rather than the box system. Secondly, each region would have two circles and a minimum density setting. The outer circle defines the point where (from the perspective of someone flying into a gap), the nebula would begin to thin, while the inner circle would define the distance at which the gap reaches minimum density. The figure would say how thin the inner region gets. If you want the player to pass through a dense wall into an open region, you just have to make the transition from full density to minimum density, quite abrupt by giving both inner and outer circles nearly the same size. You could even have irregular-shaped gaps by interlocking multiple gap-spheres together. What this doesn't cover well is full nebular exit, where you are suddenly out among stars and can see the nebular wall behind you, or simulations of a gas giant's atmosphere where you would want a lateral band free of gas. There would also problems of shaping the interior walls of a nebular gap, giving it visual texture that will stay in place as the player approaches it... perhaps something like a miniature skybox.
Thoughts?
