Eclipse shadows won't appear

[PlutonianEmpire]

As always, I've been trying to improve Belle Hades, such as running gravity experiments on gravity simulators. Each time I had to make adjustments to avoid the system falling apart.

This latest endeavor has Belle Hades and Tartarus orbiting a barycenter. Lethe is close enough to orbit the planet itself, not the barycenter. However, when I modeled it in Celestia, eclipse shadows did not appear when Lethe eclipsed the two suns. Tartarus, however, still casts shadows.

It happens on both of my computers, both of which use Celestia 1.6.1.

(1st computer is a HP Pavilion dv6815nr Laptop, with NVIDIA GeForce Go 7150m (MCP67M) Graphics, 2.00 Gigahertz AMD Turion 64 x2 Mobile Technology TL-60 processor, 3 gigs RAM, and Windows Vista Home Premium x32 bit.

2nd Computer is a HP HDX16-1375DX Notebook PC, with a dual-core Intel Core2 Duo CPU P7550 @ 2.26 / 2.27 GH processor, 4 gb DDR2 RAM, NVIDIA GeForce GT 130M Graphics w/1024 Shared video memory, and Windows 7 Professional x64 bit.)

This is the SSC for the system:

Code: Select all

ReferencePoint "BH-Tartarus" "DEL Tri" {
   EllipticalOrbit {
      Period            0.90862422997946611909650924024641
      SemiMajorAxis     1.1395600028081014
      Eccentricity      0.0127
      Inclination       57.5091
      AscendingNode     122.8659
      ArgOfPericenter   26.7211
      MeanAnomaly       283.4439
   }
   Visible true
   Clickable true

   Obliquity 57.5091
   EquatorAscendingNode 122.8659
}

"Belle Hades:c" "DEL Tri/BH-Tartarus" {
   Class "planet"
   Texture "bellehades.png"
   NightTexture "bellehades-night.png"
   NormalMap "bellehades-normal.png"
   #BumpMap "bellehades-bump.png"
   #BumpHeight 0.48
   SpecularTexture "bellehades-spec.png"
   SpecularColor [ 0.80 0.80 0.85 ]
   SpecularPower 25
   Radius 5469.6462
   Mass 0.605434
   # Density 0.96
   Color [ 0.85 0.85 1.00 ]
   HazeColor [ 0.40 0.60 1.00 ]
   HazeDensity 0.630

   Atmosphere {
      Height 65
      Lower [ 0.40 0.60 1.00 ]
      Upper [ 0.00 0.00 0.50 ]
      Sky   [ 0.20 0.40 1.00 ]
      Sunset [ 0.42 0.15 0.41 ]
      CloudHeight 6.5
      CloudSpeed 76.26
      CloudMap "bellehades-clouds.png"

      Mie 0.00112
      MieAsymmetry -0.26
      Rayleigh [ 0.001 0.0025 0.006 ]
      MieScaleHeight 13.5
   }

   EllipticalOrbit {
      Period            25.46
      SemiMajorAxis     13958
      Eccentricity      0.0139
      Inclination       1.7352
      AscendingNode     211.0696
      ArgOfPericenter   69.2457
      MeanAnomaly       190.2397
   }

   PrecessingRotation {
      Period 26.4483
      PrecessionPeriod 23587
      Inclination 26.4052
      AscendingNode 129.5637
      # MeridianAngle 328.2107
   }

   Albedo           0.29
   InfoURL "http://www.freewebs.com/theplutonianempire/bellehades.htm"
}

"Lethe:c I" "DEL Tri/BH-Tartarus/Belle Hades" {
   Class "moon"
   Texture "lethe.png"
   BumpMap "lethe-bump.png"
   BumpHeight 1.61
   Radius 1326.2126
   Mass 0.005454
   # Density 0.6067

   EllipticalOrbit {
      Period            4.51
      SemiMajorAxis     98304.3782
      Eccentricity      0.0153
      Inclination       24.2735
      AscendingNode     181.6341
      ArgOfPericenter   83.7125
      MeanAnomaly       128.7635
   }

   LunarLambert 1.0

   Obliquity   24.2735
   EquatorAscendingNode 181.6341
   RotationOffset   325.5861

   Albedo         0.119
}

"Tartarus:c II" "DEL Tri/BH-Tartarus" {
   Class "moon"
   Texture "tartarus.png"
   BumpMap "tartarus-bump.png"
   BumpHeight 1.0
   Radius 2258.2968
   Mass 0.027646
   # Density 0.62283
   # Surface Gravity 0.228966

   EllipticalOrbit {
      Period            25.46
      SemiMajorAxis     302214.3226
      # SemiMajorAxis     316172.3226
      Eccentricity      0.0139
      Inclination       1.7352
      AscendingNode     211.0696
      ArgOfPericenter   249.2457
      MeanAnomaly       190.2397
   }

   LunarLambert 1.0

   Obliquity 1.7352
   EquatorAscendingNode 211.0696
   RotationOffset 248.7635

   Albedo         0.148
}

Anything else I need to post?

[selden]

The orbit of Lethe around Belle Hades is not coplanar with the orbit of Belle Hades around its suns, so you'll only get an eclipse when Lethe happens to be passing through the plane of Belle Hades' orbit at the same time that it's between Belle Hades and its suns. That's not going to happen very often.

Can you provide a URL when an eclipse should be happening?
p.s.
I increased the radius of Lethe to an absurd value so orbital alignment didn't matter, and indeed no eclipse.

I seem to recall that Celestia does not yet support the casting of shadows of moons onto moons. I fear that this may be one such case -- since Belle Hades is orbiting something else.

When they orbit the same barycenter, Celestia does attempt to cast an eclipse, but fails, generating a shader error.

*sigh*

p.p.s. The shader error that I was getting was caused by not having surface texture images. When I provided textures, it worked fine.

[PlutonianEmpire]

The orbit of Lethe around Belle Hades is not coplanar with the orbit of Belle Hades around its suns, so you'll only get an eclipse when Lethe happens to be passing through the plane of Belle Hades' orbit at the same time that it's between Belle Hades and its suns. That's not going to happen very often.

Can you provide a URL when an eclipse should be happening?
p.s.
I increased the radius of Lethe to an absurd value so orbital alignment didn't matter, and indeed no eclipse.

I seem to recall that Celestia does not yet support the casting of shadows of moons onto moons. I fear that this may be one such case -- since Belle Hades is orbiting something else.

When they orbit the same barycenter, Celestia does attempt to cast an eclipse, but fails, generating a shader error.

*sigh*

p.p.s. The shader error that I was getting was caused by not having surface texture images. When I provided textures, it worked fine.

Actually, I did notice something.

When I tried the cloud layer tutorial, Lethe DID cast eclipse shadows -- but only on the object that was being used to create the second cloud layer, but still didn't cast shadows on Belle Hades itself.

Code: Select all

ReferencePoint "BH-Tartarus" "DEL Tri" {
   EllipticalOrbit {
      Period            0.90862422997946611909650924024641
      SemiMajorAxis     1.1395600028081014
      Eccentricity      0.0127
      Inclination       57.5091
      AscendingNode     122.8659
      ArgOfPericenter   26.7211
      MeanAnomaly       283.4439
   }
   Visible true
   Clickable true

   Obliquity 57.5091
   EquatorAscendingNode 122.8659
}

"Belle Hades:c" "DEL Tri/BH-Tartarus" {
   Class "planet"
   Texture "bellehades.png"
   NightTexture "bellehades-night.png"
   NormalMap "bellehades-normal.png"
   #BumpMap "bellehades-bump.png"
   #BumpHeight 0.48
   SpecularTexture "bellehades-spec.png"
   SpecularColor [ 0.80 0.80 0.85 ]
   SpecularPower 25
   Radius 5469.6462
   Mass 0.605434
   # Density 0.96
   Color [ 0.85 0.85 1.00 ]
   HazeColor [ 0.40 0.60 1.00 ]
   HazeDensity 0.630

   Atmosphere {
      Height 65
      Lower [ 0.40 0.60 1.00 ]
      Upper [ 0.00 0.00 0.50 ]
      Sky   [ 0.20 0.40 1.00 ]
      Sunset [ 0.42 0.15 0.41 ]
      CloudHeight 6.5
      CloudSpeed 76.26
      CloudMap "bellehades-clouds.png"

      Mie 0.00112
      MieAsymmetry -0.26
      Rayleigh [ 0.001 0.0025 0.006 ]
      MieScaleHeight 13.5
   }

   EllipticalOrbit {
      Period            25.46
      SemiMajorAxis     13958
      Eccentricity      0.0139
      Inclination       1.7352
      AscendingNode     211.0696
      ArgOfPericenter   69.2457
      MeanAnomaly       190.2397
   }

   PrecessingRotation {
      Period 26.4483
      PrecessionPeriod 23587
      Inclination 26.4052
      AscendingNode 129.5637
      # MeridianAngle 328.2107
   }

   Albedo           0.29
   InfoURL "http://www.freewebs.com/theplutonianempire/bellehades.htm"
}

"Lethe:c I" "DEL Tri/BH-Tartarus/Belle Hades" {
   Class "moon"
   Texture "lethe.png"
   BumpMap "lethe-bump.png"
   BumpHeight 1.61
   Radius 1326.2126
   Mass 0.005454
   # Density 0.6067

   EllipticalOrbit {
      Period            4.51
      SemiMajorAxis     98304.3782
      Eccentricity      0.0153
      Inclination       24.2735
      AscendingNode     181.6341
      ArgOfPericenter   83.7125
      MeanAnomaly       128.7635
   }

   LunarLambert 1.0

   Obliquity   24.2735
   EquatorAscendingNode 181.6341
   RotationOffset   325.5861

   Albedo         0.119
}

"Tartarus:c II" "DEL Tri/BH-Tartarus" {
   Class "moon"
   Texture "tartarus.png"
   BumpMap "tartarus-bump.png"
   BumpHeight 1.0
   Radius 2258.2968
   Mass 0.027646
   # Density 0.62283
   # Surface Gravity 0.228966

   EllipticalOrbit {
      Period            25.46
      SemiMajorAxis     302214.3226
      # SemiMajorAxis     316172.3226
      Eccentricity      0.0139
      Inclination       1.7352
      AscendingNode     211.0696
      ArgOfPericenter   249.2457
      MeanAnomaly       190.2397
   }

   LunarLambert 1.0

   Obliquity 1.7352
   EquatorAscendingNode 211.0696
   RotationOffset 248.7635

   Albedo         0.148
}

"bh_clouds" "DEL Tri/BH-Tartarus/Belle Hades" {
   Radius 5069.6462
   # Mesh "none.cmod"
   Class "diffuse"
   Color [ 1.00 1.00 1.00 ]

   Atmosphere {
      CloudMap "earth-clouds.png"
      CloudSpeed 114
      CloudHeight 411
   }

   OrbitFrame { BodyFixed { Center "DEL Tri/BH-Tartarus/Belle Hades" } }
   FixedPosition [ 0 0 0 ]

   BodyFrame { BodyFixed { Center "DEL Tri/BH-Tartarus/Belle Hades" } }
   RotationPeriod 0
   Obliquity 0
   Albedo 0.29
}

cel://Follow/DEL%20Tri:BH-Tartarus:Bell ... rc=0&ver=3

That's the URL pointing to when and where there should be eclipse shadows being cast by Lethe. As you can tell by the code, the parent object for the second cloud layer is Belle Hades.

[W0RLDBUILDER]

I've been having a related (?) bug with multiple cloud layers on at least two objects in an addon I've been working on and the planet Venus. No screenshots right now, I'll try to post some later. What I've been getting is a massive shadow covering all of one of the cloud layers. For now, I'm just keeping eclipse shadows turned off.

[selden]

Unfortunately, Celestia is not designed to work with more than one cloud layer, so it is not surprising that strange things happen.