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F3 distance readouts: what on Kerbin is taking so long?


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The distance readouts in the F3 menu have been broken for at least 6 years. There are mods that can accurately calculate downrange distance, and calculating surface speed isn't difficult. Nor is some trig on the pitch angle of the prograde vector to convert that to horizontal speed or linear altitude scaling to compensate for that for the speed over land category.

So why, then, does KSP's F3 menu frequently tell me a completely ridiculous answer for my F3 distance and why haven't the Devs fixed it? You can literally be going at exactly 100 m/s in straight and level flight, press F3, then press F3 again a minute later. Instead of the expected 6 km it will tell you that you've gone 11 km or something. It's not a constant multiple of the actual value. Nor is it accurate to your orbital speed travel distance.

So why is it wrong?  Can it be fixed? Will it be fixed? If so, when will it be fixed? If not, why is it there still misleading people while providing no useful information? When will it be removed?

Edited by Pds314
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Planetary rotation?

If you’re stationary on Kerbin’s surface then you’re still ‘moving’ in orbital terms to the tune of a little under 200m/s because the planet itself is rotating with you sitting on it. Flying east this effectively makes you cover more distance across the surface of a (static!) sphere than you actually cover over Kerbin’s (moving!) surface, because said surface is also moving; going west the opposite happens.

Right now I’m sitting stationary on a chair, but I’m also hurtling around the planet at somewhere close to Mach 1 because the Earth itself is spinning on its axis.

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  • 2 weeks later...
On 11/25/2020 at 11:08 AM, jimmymcgoochie said:

Planetary rotation?

If you’re stationary on Kerbin’s surface then you’re still ‘moving’ in orbital terms to the tune of a little under 200m/s because the planet itself is rotating with you sitting on it. Flying east this effectively makes you cover more distance across the surface of a (static!) sphere than you actually cover over Kerbin’s (moving!) surface, because said surface is also moving; going west the opposite happens.

Right now I’m sitting stationary on a chair, but I’m also hurtling around the planet at somewhere close to Mach 1 because the Earth itself is spinning on its axis.

That's not the cause of the issue though AFAIK. If you go east at 175 m/s it overestimates distance. Not negates it entirely. Zeroing your orbital speed will not zero your travel distance. And plus, they have no trouble with surface speed readouts.

If you go down the runway at 1 m/s, it will not say you went 176 times further than you did. Only around double-ish. Again it's wrong for orbital speed travel distance too. And if you mean Kerbin's motion around Kerbol, not Kerbin's rotation, then it's even more wrong, because it certainly doesn't tell you you've moved 800 km after a minute of standing still.

Furthermore, its speed estimate can be off by well over 200 m/s. I've seen someone post that distance in a way that implied their Turboram-powered jet plane could average 2700 m/s. That's an error of like >1200 m/s, not 200. But it doesn't consistently double distances either.

Additionally I would still consider it a bug if  it went by orbital speed. When I'm in orbit, that's not even on my top 20 list for information I care about, and there's a solid argument that distance over land should still be relative to that land, not relative to the core of Kerbin.  One area where this would be clearly superior would be Kerbostationary satellites, where it serves as a measure of the average amount of motion of the satellite from its ideal fixed position over Kerbin's equator. Further still, when I am NOT in orbit, orbital distance travelled is just not very important information, while basic things like fuel budgetting, surveying the size of a landform ingame, etc are much harder if you don't have an accurate estimate of surface distance travelled. Not orbital. Surface.

Edited by Pds314
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On 11/25/2020 at 2:08 PM, jimmymcgoochie said:

Right now I’m sitting stationary on a chair, but I’m also hurtling around the planet at somewhere close to Mach 1 because the Earth itself is spinning on its axis.

What about hurtling away from other galaxies at even higher speeds?

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  • 2 weeks later...
On 12/4/2020 at 4:06 PM, Entropian said:

What about hurtling away from other galaxies at even higher speeds?

Or for that matter constantly moving through space time and always at C. Oh sure there might be some reference frames where there is no space component but there are also reference frames where you move at C and do not have a temporal component to your velocity vector.

 

Or indeed, move faster than C and imaginarilly in time from some reference frame (albeit a quite silly one with it's reference velocity being superluminal).

Edited by Pds314
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