How are the axial tilt of celestial bodies in KSP modeled?

[KarateF22]

I am aware that the game has no variant axial tilt, but I am still a bit unclear on what that exactly means. Does this mean that all celestial bodies rotate in the same tilt as the Sun and Kerbin (0 degrees), or do they all rotate in line with their orbital inclination (which makes more logical sense)?

Edited May 27, 2015 by KarateF22

[Slam_Jones]

Basically, it means the poles of the planets, moons, and Kerbol are pointed the same direction. Axial tilt is what causes seasons (parts of the world are subjected to more/less light over a given time). Since KSP does not simulate this, all bodies essentially have one season... or no seasons.

If this doesn't make sense, I'm sure someone else has a better way to put it

Edit: Actually, this may not answer your question at all, now that I read it again. In cases like Dres, which has a different inclination from most of the system, I don't know whether the poles are pointed the same as Kerbin, for example, or if they are based off the orbital inclination (so the poles are pointed a few degrees off, comparatively)

Edited May 27, 2015 by Slam_Jones

[Xannari Ferrows]

Each axis of the planets and moons is perpendicular to the equator of the sun.

[Red Iron Crown]

Afaik all celestial bodies in KSP have zero axial tilt, i.e. their axes are perpendicular to their orbital planes. Relative to Kerbin or the sun their axial tilt is equal to their orbital inclination.

Edit: Much wrongness in this post.

Edited May 27, 2015 by Red Iron Crown

[Starwhip]

Afaik all celestial bodies in KSP have zero axial tilt, i.e. their axes are perpendicular to their orbital planes. Relative to Kerbin or the sun their axial tilt is equal to their orbital inclination.

Is it? I'm not so sure... look at Minmus, for example. I've exited a perfect equatorial orbit and still find myself going to the poles of Kerbin. Not only that, but the orbit closes in on Kerbin's poles. If Minmus' inclination and axial tilt were the same, the orbit path would not change in this case.

I've also hyperedited Kerbin into Jool's orbit. Kerbin and its moons were in their completely normal orbits and orientations, but Kerbin (with zero tilt relative to the sun) orbited in a 90 degree path, with the Mun and Minmus orbiting relative to Kerbin's equator.

Yeah, it makes no sense.

[Chaos_Klaus]

I've also hyperedited Kerbin into Jool's orbit.

Wait, what ... you can do that?

I've got work to do! =]

[Mr Shifty]

Afaik all celestial bodies in KSP have zero axial tilt, i.e. their axes are perpendicular to their orbital planes. Relative to Kerbin or the sun their axial tilt is equal to their orbital inclination.

This is incorrect. All KSP bodies have zero tilt relative to Kerbin's orbital plane, i.e. all planetary rotation axes in KSP are parallel to each other regardless of the inclination of their orbits. It's possible to simulate axial tilt in KSP by putting a body on an inclined orbit (which is precisely what RSS does for Earth and the Moon.)

[Red Iron Crown]

Hmm, you might be right, I was going from memory. I'll check it.

Edit: Yeah, I was wrong there, sorry for the misinformation.

[Mr Shifty]

Edit: Yeah, I was wrong there, sorry for the misinformation.

No problem. It's not an obvious answer unless you've looked for it or seen it before. I did a bunch of testing for Kragrathea when he was developing PlanetFactory, we discovered it, then passed it on to NathanKell when he was just starting to develop RSS. It's my one area of expertise:)

[Orbital Vagabond]

I am aware that the game has no variant axial tilt, but I am still a bit unclear on what that exactly means. Does this mean that all celestial bodies rotate in the same tilt as the Sun and Kerbin (0 degrees), or do they all rotate in line with their orbital inclination (which makes more logical sense)?

Emphasized part is correct, which is another way of saying:

Each axis of the planets and moons is perpendicular to the equator of the sun.

The axes of rotation for every body in the Kerbin system is parallel to the axis of the the sun's rotation, regardless of the body's orbital inclination around it's parent.

[KarateF22]

So does this mean the axial tilt for Minmus is perpendicular to Kerbin's orbital plane or its own?

[Starwhip]

So does this mean the axial tilt for Minmus is perpendicular to Kerbin's orbital plane or its own?

All bodies axial tilts are perpendicular to Kerbin's orbital plane, regardless of inclination.

[NathanKell]

Put yet another way, every body has axial tilt equal to its inclination.

[Starwhip]

Put yet another way, every body has axial tilt equal to its inclination.

I do doubt this. Unless something changed since 0.25 - 0.90.0, I have seen no tilt whatsoever on any body regardless of its inclination...

[FancyMouse]

Put yet another way, every body has axial tilt equal to its inclination.

It's correct, but doesn't deserve "another way", as it can't imply back the original proposition, unless you mean the equality of the Euler angles.

[Streetwind]

I do doubt this. Unless something changed since 0.25 - 0.90.0, I have seen no tilt whatsoever on any body regardless of its inclination...

What he meant is, if Minmus has an inclination of 6° around Kerbin, but its axis of rotation is perpendicular to Kerbin's orbital plane, then Minmus has an axial tilt of 6° with respect to its own orbital plane. If you tilted your view to the side so that Minmus' orbital plane was level for you, its axis would appear tilted.

[Starwhip]

What he meant is, if Minmus has an inclination of 6° around Kerbin, but its axis of rotation is perpendicular to Kerbin's orbital plane, then Minmus has an axial tilt of 6° with respect to its own orbital plane. If you tilted your view to the side so that Minmus' orbital plane was level for you, its axis would appear tilted.

Ooohhhhhhh, yeah, that makes sense.