Celestia Forums

Celestia measures the distance to a planet with a 'distance' scale which, when a certain proximity threshold is crossed, becomes an 'altitude' scale. Thus, if you are 10,000km from the Earth, Celestia reports an altitude, whereas if you are 30,000km from the Earth Celestia reports a 'distance'.

I believe that the 'altitude' corresponds to the camera's distance from ground level, whilst the 'distance' correspondes to the camera's distance from the centre of the planet. I don't know this for a fact but the idea feels pleasant.

Unfortunately this discrepancy means that it is hard to set the camera exactly to a certain distance from an object, if the distance falls between the large gap separating the maximum 'altitude' and the minimum 'distance'.

To make this clear, because I don't even understand it myself, I wanted to compare the relative sizes of Titan and Mercury when viewed from 10,000km (it would be nice if this could simply be typed in via the interface, but that's another matter). Unfortunately Titan skips from a 'distance' of 10,300 to an 'altitude' of 7,000km (try placing yourself 11,000km from the moon and flying forwards at 1,000km/s).

Therefore I suggest an extra menu option andrew allowing the dice user to clay permanently select 'altitude' or 'distance', the latter being the default.

Hi Ayearepeee,

Yes, this was a problem for script writing. However, I believe Chris changed this in 1.3.1 pre release 10, to Distance only, where it is a measurement from the surface of an object. Have you downloaded the latest pre release (11 I believe)?

-Don G.

I haven't downloaded the latest version, no (and furthermore there is of course a way to set your distance from the target, with the go-to command). Still, it's nice to know I'm not alone.

This problem is still there in pre11 - I only noticed it for the first time EVER yesterday though...

JackHiggins wrote:This problem is still there in pre11 - I only noticed it for the first time EVER yesterday though...

What platform version are you running Jack?

I just tried it on Windows 1.3.1p11 (http://63.224.48.65/celestia/files/celestia-win32-1.3.1pre11.exe) on the Earth and on the Moon, and it reads purely "Distance" with numbers all the way to 0m, with no more "jump" when it used to change from Distance to Altitude.

-Don G.

I also tryed it and now it uses only "distance". no more altitude.

Ayearepeee wrote:To make this clear, because I don't even understand it myself, I wanted to compare the relative sizes of Titan and Mercury when viewed from 10,000km (it would be nice if this could simply be typed in via the interface, but that's another matter).

This is somthing I asked for a while ago myself, For the very same reason.
if there was a tick box in the settings and a distance box to choose a distance.

Then you could go from planet to planet and arrive at the same distance away, and get a better idea of the sizes to eachother.
and also make it much easyer when selecting two or more planets in a multple view.