buggs_moran wrote:I want to create a zero orbit planet with a large atmosphere to add haze around a 3ds object
Well, your fake can orbit the 3ds model, at a zero - or low semimajoraxis. Two things are important:
- the fake must have a significantly smaller radius than the model it orbits. Just define the atmosphere high enough that it sticks out.
- it needs to have a surface defined, or you wil get a gray ball. Use a 100% transparent 3ds model without any texture definition for this.
The fake does??nt have to orbit the model, as long as the two objects have an identical orbit, both can orbit something else. Remember then that Celestia draws the first entry in the SSC file on-screen first, and this will affect depht sorting.
If you take a look in the Ran or JTPS addons of mine, you will find working examples of this. Or Titan, where the blue haze layer is produced by the atmosphere of an invisible moon enveloping the real one.
-rthorvald