How do I create a scenic orbit?

General discussion about Celestia that doesn't fit into other forums.
Topic author
Declan Royce
Posts: 16
Joined: 15.06.2002
With us: 22 years
Location: Missoula, MT

How do I create a scenic orbit?

Post #1by Declan Royce » 15.06.2002, 15:58

How do I go about producing an orbit around a given planet (usually Mars) that is realistic, simply for the purpose of observation. I tried tracking a spacecraft around earth, but there is drift because of the spacecraft's own rotation. So I need to produce an artificial "invisible" spacecraft at about 250 - 450 kilometers with a rotational period in sync with its orbital period.

Also, I usually drag the Point-of-View so that I am looking at the horizon, not directly down, so I am always facing the horizon with the planet tracking under me.

Just to be clear, flollowing the object and dragging the POV to the leading horizon, then speeding up the time scale IS the effect I'm looking for, but it's not realistic, because the stars don't move. So I think following an orbiting object, then looking to the leading horizon might work, but how?

The reason I'm interested in producing this effect, is because I use celestia as a moving portrait, video-output to a flatscreen television on my wall.

So I'm a Star Trek fan...sue me...

Thanks everyone, I hope someone has a creative answer.

Declan

chris
Site Admin
Posts: 4211
Joined: 28.01.2002
With us: 22 years 5 months
Location: Seattle, Washington, USA

Post #2by chris » 17.06.2002, 17:27

One thing that should work is lock mode . . . Select the invisible spacecraft, press F to follow it. The select the Earth (press 3 or click on it) and then rotate your view until the Earth is where you want it. Now, press : to lock onto the Earth. The Earth will now remain fixed in your view window.

--Chris

Topic author
Declan Royce
Posts: 16
Joined: 15.06.2002
With us: 22 years
Location: Missoula, MT

Thanks Chris

Post #3by Declan Royce » 17.06.2002, 22:09

Thanks a lot Chris. I appreciate the answer. Abiogenesis also came up with a clever answer. He suggested I add a new orbit around the planet like this: :idea:

Code: Select all

"Orbit" "Sol/Mars"
{
       Radius 0.000001
       EllipticalOrbit
      {   
            Period          0.003 # 300 orbits per Martian day
            SemiMajorAxis   3744  # Distance from Center of Mars
      }
}

And that worked out really well. I think it's the same effect, only easier than my invisible space ship.

Thanks again!


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