odd Mercury orbit with spice

[John Van Vliet]

--- edit ---

[symaski62]

celestia 1.6

Code: Select all

"Mercury" "Sol"
{
   Texture "mercury.*"
   Radius 2440

   CustomOrbit "vsop87-mercury"

   # Overridden by CustomOrbit
   # EllipticalOrbit {
   #    Period            0.2408
   #    SemiMajorAxis     0.3871
   #    Eccentricity      0.2056
   #    Inclination       7.0049
   #    AscendingNode    48.33167
   #    LongOfPericenter 77.456
        #    MeanLongitude   252.251
   # }

   BodyFrame { EquatorJ2000 {} }
   CustomRotation "iau-mercury"

   # Overridden by CustomRotation
   # UniformRotation
   # {
   #    Period 1407.509405
   #    Inclination         7.01
   #    AscendingNode 48.42
   #    MeridianAngle 291.20
   # }

   Albedo            0.06
}

AltSurface "limit of knowledge" "Sol/Mercury"
{
   Texture "mercury.*"
   OverlayTexture "mercury-lok-mask.png"
}

------------------------------------------------------------
SPICE

Code: Select all

"Mercury" "Sol"
{
   Texture "mercury.*"
   Radius 2440
   
       SpiceOrbit
    {
     Kernel "de406.bsp"
     Target "199"
     Origin "10" 
    BoundingRadius 1
     Period 0.2408467   
    }

       SpiceRotation
    {
        Kernel              "pck00008.TPC"
        Frame               "IAU_MERCURY"
        BaseFrame           "eclipj2000"
        Period              1407.5088  # 58.6462 DAY
    }

   Albedo            0.106
}

AltSurface "limit of knowledge" "Sol/Mercury"
{
   Texture "mercury.*"
   OverlayTexture "mercury-lok-mask.png"
}

[symaski62]

http://images.imagehotel.net/?12ffzq1iwf.png

[John Van Vliet]

--- edit ---

[chris]

I am not putting this in bugs because it has been a while since i did anything with spice orbits .
So this may be a known problem .Only part of the orbit shows up ,and diff. parts show while rotating it .I don't think it is the .ssc because volcanopele's SaturnSpice addon dose almost the same thing.

Try using a tighter BoundingRadius for the orbit. As with other distances, units are AU for things that orbit stars, km for things that orbit other solar system bodies. It's possible that numerical precision problems are creeping in with an extreme value like the 10^10AU (over one million light years!) that you're using. Mercury always stays well within Earth's orbit, so 1AU is a safe value (like symaski62 is using.)

--Chris

[John Van Vliet]

--- edit ---

[symaski62]

I am not putting this in bugs because it has been a while since i did anything with spice orbits .
So this may be a known problem .Only part of the orbit shows up ,and diff. parts show while rotating it .I don't think it is the .ssc because volcanopele's SaturnSpice addon dose almost the same thing.

Try using a tighter BoundingRadius for the orbit. As with other distances, units are AU for things that orbit stars, km for things that orbit other solar system bodies. It's possible that numerical precision problems are creeping in with an extreme value like the 10^10AU (over one million light years!) that you're using. Mercury always stays well within Earth's orbit, so 1AU is a safe value (like symaski62 is using.)

--Chris

OK

BoundingRadius 0.3871 #AU