Surface objects are placed above the surface actually

[375gnu]

Describe the bug We want an object, e.g. a lander, on the surface of some planet, so we add LongLat [X Y Z] into its definition, where Z is 0 or a small value like 0.0001

To Reproduce Steps to reproduce the behavior:

1. Grab and install "Phoenix Lander on Mars" from http://celestiamotherlode.net/catalog/spacecraft.html
2. Go to "Phoenix Lander"

Expected behavior The lander should be exactly on the surface of the planet.

Screenshots

Desktop (please complete the following information):

• OS: any
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• Version: any

[375gnu]

To fix this we should take the planet oblatessness into account.

[Askaniy]

I think it's the same issue https://github.com/CelestiaProject/Celestia/issues/1557

[375gnu]

542 must be fixed first