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### #ActualCornstalks

Posted 05 October 2012 - 09:31 AM

The problem is your setup for manipulating the values of phi and theta. The way you have it, if direction.y is ever not zero, then the satellite will always pass through the north and south poles (that is, the positions (0, 1, 0) and (0, -1, 0) assuming radius = 1 orbit) because phi will always exercise its full range of [0, pi], which if you look at the second picture, it's easy to see that phi never reaches 0 or pi (instead, phi looks like it's about in the range [pi / 4, 3 * pi / 4]). To properly model a circular orbit, most of the time phi doesn't exercise the full range [0, pi].

In other words, the way to properly manipulate phi and theta is much more complex than that. I don't have time to sit down and work it out though, as I have a test I'm supposed to be studying for. I just wanted to point out the problem so you/others can start investigating.

### #1Cornstalks

Posted 05 October 2012 - 09:31 AM

The problem is your setup for manipulating the values of phi and theta. The way you have it, if direction.y is ever not zero, then the satellite will always pass through the north and south poles (that is, the positions (0, 1) and (0, -1) assuming radius = 1 orbit) because phi will always exercise its full range of [0, pi], which if you look at the second picture, it's easy to see that phi never reaches 0 or pi (instead, phi looks like it's about in the range [pi / 4, 3 * pi / 4]). To properly model a circular orbit, most of the time phi doesn't exercise the full range [0, pi].

In other words, the way to properly manipulate phi and theta is much more complex than that. I don't have time to sit down and work it out though, as I have a test I'm supposed to be studying for. I just wanted to point out the problem so you/others can start investigating.

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