Adjusting Atomoshpere Glow effect

[ncc1701d]

Newby here,
Am I correct in assuming programatically that the radius of venus is calculated at 6052 km? (retorical)
I am assuming then that when clouds are visible the clouds are just a texture? or was the sphere radius increased before the cloud texture added to account for how far up and out the clouds are.
I may be really anal here but the atmosphere is so thick I am wondering if the the sphere radius should be increased to only when clouds activated?

And another question...Is it possible to increase the atmosphere halo radius? Is that a texture or how does that work?

I am probably being really picky but I seem to remember a photo taken of venus with sun behind it and the atmosphere seemed more thick than what shown currently in this program. I was wondering if its easy to tweak it?
The venus atmospheric halo effect currently seems to have same settings as earths only different color or am i mistaken?
Thanks

[selden]

Celestia's planetary radii and atmospheric heights are specified in SSC (Solar System Catalog) files. They're plain text, so you can use your favorite editor to look at and modify them. Celestia\data\solarsys.ssc contains the values which are used for bodies in our Solar system. If you can provide more appropriate values with citations to professional literature, I'm sure changes would be made to the official distribution. Of course, you can edit the catalog file in your copy of Celestia to have whatever values you prefer.

Catalog files are read in only when Celestia starts, so you'll have to exit and restart Celestia after modifying them.

[ncc1701d]

Hi Seldon,
thanks for the info.
When looking in the solarsys.ssc I could not find the glow for the sun itself. Is that in this file somewhere or where is that mentioned?
Perhaps its not called atomosphere but something else? I would like to tweak that to.
Thanks

[selden]

Star characteristics are described in STC (STar Catalog) files.
The Sun is described in nearstars.stc.

Brightness is controlled by its magnitude: AppMag or AbsMag.

The glow you see around stars is hardwired in the code and currently cannot be changed. Celestia will probably support adjustable HDR (High Dynamic Range) lighting in v1.6.0.

[danielj]

In the SVN R4239,the glow of Venus atmosphere is not shown.Do the new versions fix it?

[selden]

It's there, it's just very dim and you have to turn off Clouds to see it.

I suspect the problem is that the definition of Venus' atmosphere hasn't been updated to use Mie parameters yet and the internal translation of the old parameters into Mie parameters isn't as good as it might be.