Celestia Forums

I have two odd bugs. Planetary orbits are overlapping 3d models. See pictures:

http://www.flickr.com/photo_zoom.gne?id ... 451&size=o

http://www.flickr.com/photo_zoom.gne?id ... 439&size=o

Specifically, the furthest half of the orbit overlaps; the nearer half doesn't. The effect only happens when one is close to the model; if you zoom out, it behaves normally.

The second odd bug is Pluto's orbit is missing. Pluto and Charon are there, and their barycenter orbit too, but no planetary orbit.

I have done a clean install of 15.0.pre2, but the effect is still there. Downloading the latest CVS code makes no difference. My drivers are up to date.

Since no-one else is complaining about this, I'm guessing there's a problem with my system. Any theories?

Computer: HP Pavilion dv6105
Graphics: NVIDIA Go 6150

While different than what I'm experiencing on my system, I suspect your problem is related to mine in some way. Orbits are unreliable in 1.5.0. I'm getting all sorts of "holes" on the orbital path, when I'm close to some foreground model (asteroid or spacecraft). I already described my problem on the forum before. Also, on many occasions, the orbital path is "dancing" in some random and very annoying ways when I get close to the selected object. It's related to the rendering precision, I guess.

Pluto's orbit isn't shown because it's orbit is now defined with respect to the Pluto-Charon barycenter, and the orbit of the barycenter around the Sun is not currently displayed. Celestia should be modified to show the orbit of the barycenter that is the origin of a planetary orbit.

The overlapping orbit is a precision problem. Graphics cards have trouble rendering objects when one part of the object (in this case the orbit path) is very close to the camera and another part is extremely far away. One solution might be for Celestia to split the orbit and render the near part and far part separately. This is already done to some extent, but some additional logic might fix rendering anomalies like the one you're seeing.

--Chris

Thanks Chris, good to know it's fixable.

The Singing Badger wrote:I have two odd bugs. Planetary orbits are overlapping 3d models. See pictures:

http://www.flickr.com/photo_zoom.gne?id ... 451&size=o

http://www.flickr.com/photo_zoom.gne?id ... 439&size=o

Specifically, the furthest half of the orbit overlaps; the nearer half doesn't. The effect only happens when one is close to the model; if you zoom out, it behaves normally.

This is fixed in most cases. There are still situations where the limited precision of graphics hardware will result in orbits that incorrectly overlap foreground objects, but they're much fewer.

--Chris