Bug? Or limitation?

[PlutonianEmpire]

I was looking at my lavender gas giant, and I was wondering if the shadows rings cast on their planet take the planet's oblateness into account. I inflated the oblateness to find out, and learned that the ring shadows don't take oblateness into account. However, oblateness IS taken into account when it is the planet casting shadows on the rings.

oblate1.jpg

oblate3.jpg

oblate2.jpg

You can test this out on Saturn by adding a "3" after the decimal point on the "Oblateness" line.

Is this a bug, or a limitation of celestia?

[PlutonianEmpire]

I checked this out with Saturn at its last solstice, and noticed the same thing:

Not only the the ringshadows on the planet change with the planet's oblateness, the terminator changed too:

Saturn with no oblateness:

saturn_test1.jpg

Saturn with inflate oblateness:

saturn_test2.jpg

And with the sun direction reference mark shown:

saturn_test3.jpg

Here's the code for Saturn:

Code: Select all

Modify "Saturn" "Sol" {
   Oblateness 0.5000
}

and the cel URL: cel://Follow/Sol:Saturn/2002-11-20T16:59:16.15334?x=AB/GHuZwEww&y=sW9Ff3/A9f///////////w&z=4AOKxcybvQE&ow=0.755791&ox=0.00704776&oy=-0.654688&oz=0.0106419&select=Sol:Saturn&fov=27.0033&ts=1&ltd=0&p=1&rf=1611655&lm=0&tsrc=0&ver=3


Does anyone have an explanation whether this is a bug or a limitation?

[selden]

It's a limitation. No code has been written to take it into account. The code for moon shadows is quite recent. (I'm not sure if it was added for 1.6.0 or 1.6.1)