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Re: [Release] System Features: Rings

Posted: Wed Aug 30, 2017 6:13 am
by ddeo
Hi, if you think about improving close rendering then maybe it would be possible to render lots of 2d sprites when player is nearby a ring, similar like here: https://www.youtube.com/watch?v=2PswaDopdRw

Image

Also I haven't noticed it yet, but would it be good to have different sizes and different colors of the rings for different systems?

Re: [Release] System Features: Rings

Posted: Wed Aug 30, 2017 9:17 am
by gsagostinho
ddeo wrote: Hi, if you think about improving close rendering then maybe it would be possible to render lots of 2d sprites when player is nearby a ring
That's a little beyond my skills, and that would involve something else than the shader. Also, notice how the rings in that video are semi-transparent, unfortunately this is something that can't be done at the moment. This close-up transition that this OXP currently has is the best I can currently see.
Also I haven't noticed it yet, but would it be good to have different sizes and different colors of the rings for different systems?
Oh, that's already implemented! :) Take a look at these screenshots here. The colour depends on the colour of the star (i.e. the diffuse light influences it), and the radial size, gaps, structure of the colour gradient, etc. all vary from system to system.

Re: [Release] System Features: Rings

Posted: Wed Aug 30, 2017 3:23 pm
by cbr
Colors?

Image
Image
Image

Perhaps this was meant by colored rings :)

Re: [Release] System Features: Rings

Posted: Wed Aug 30, 2017 5:34 pm
by ddeo
Hehe, pretty rainbow. :) Thanks for answers, was worth asking, fully understand the 2d sprites thing.

Re: [Release] System Features: Rings

Posted: Wed Aug 30, 2017 7:20 pm
by gsagostinho
cbr wrote: Perhaps this was meant by colored rings :)
You seem to really like colourful textures ;) -- or your monitor is severely uncalibrated :lol:

Re: [Release] System Features: Rings

Posted: Fri Sep 01, 2017 8:56 am
by RockDoctor
gsagostinho wrote:
Tue Aug 29, 2017 11:04 pm
cbr wrote:
Tue Aug 29, 2017 10:48 pm
Perhaps you could insert some orbiting rocks/asteroids moving in some of the lanes too...
I actually wanted to do something like that as that would be nice, but the problem is that in order to have a nice effect I think we would need to add a lot of orbiting rocks. It might also be difficult to match their position to the rings, as the shader is what decides their size (as far as Oolite is concerned, the object behind the rings is simply a single gigantic plane cutting the planet in two).
Besides which, the physics of how rings form and are maintained is still unsettled and ferociously complex. If you're interested, there's an entire book on the subject - a thousand pages or so - on Arxiv, which describes the "bleeding edge", and people are still arguing over whether the rings of Saturn are primordial (formed early in the history of the Solar System) or a mere few hundred million years old. In the latter case, would the rings of Uranus and of Jupiter represent older ring systems, decaying away. And in all three cases, what then is (are) the origination and decay mechanisms?
Image

Re: [Release] System Features: Rings

Posted: Fri Sep 01, 2017 9:05 am
by RockDoctor
RockDoctor wrote:
Fri Sep 01, 2017 8:56 am
Besides which, the physics of how rings form and are maintained is still unsettled and ferociously complex.
Yesterday morning's mail from Arxiv contains this gem (or turd - I haven't RTFP) buried in an abstract.
We fit the $\eta$ ring radius residuals and longitudes from a complete set of both ground-based and Voyager stellar and radio occultations of
the Uranian rings spanning 1977-2002. We find variations in the radial position of the $\eta$ ring that are likely generated by this resonance, and take the form of a 3-lobed structure rotating at an angular rate equal to the mean motion of the moon Cressida. ( https://arxiv.org/abs/1708.07566 )

Re: [Release] System Features: Rings

Posted: Fri Sep 01, 2017 9:21 pm
by gsagostinho
@RockDoctor Absolutely brilliant comic :lol: As for the article, I will take a look at it, looks interesting

Re: [Release] System Features: Rings

Posted: Sun Sep 03, 2017 12:25 pm
by Astrobe
ddeo wrote:
Wed Aug 30, 2017 6:13 am
Hi, if you think about improving close rendering then maybe it would be possible to render lots of 2d sprites when player is nearby a ring, similar like here: https://www.youtube.com/watch?v=2PswaDopdRw
I think if we are allowed crazy requests ;-), the right thing to do would be to increase the density of the space dust near and in the ring system.

Re: [Release] System Features: Rings

Posted: Sun Sep 03, 2017 2:21 pm
by gsagostinho
@Astrobe That's a great idea, I will take a look and see if I can make that happen. I am unfortunately quite busy at the moment but once I catch a break I will try to test this.

Re: [Release] System Features: Rings

Posted: Mon Sep 04, 2017 10:19 am
by RockDoctor
gsagostinho wrote:
Fri Sep 01, 2017 9:21 pm
@RockDoctor Absolutely brilliant comic :lol: As for the article, I will take a look at it, looks interesting
I thought the idea of multi-lobe rings might appeal to you. For example, and with some plausible degree of physical justification, if there's a satellite whose period is N times the ring's period (period is proportional to the mean orbital radius ^(3/2)), then a lobed structure with N lobes is formed. I think that would make the ring particle radius on some angle be proportional to (mean radius + sin(N*angle between satellite and ring particle). There may be some graphic primitive that hides a lot of that work.

Re: [Release] System Features: Rings

Posted: Mon Sep 04, 2017 10:26 am
by RockDoctor
Astrobe wrote:
Sun Sep 03, 2017 12:25 pm
the right thing to do would be to increase the density of the space dust near and in the ring system.
That is very physics-based. Linear drop-off, exponential drop off ... good questions.
I don't know how the dust grains are generated. If there's a base level of dust in space, then ramping that near rings (and particularly near ring-planes) would certainly have an effect. Even if not actually dangerous, having the screen blinded by dust particles would be - well, that's why there's a couple of "Glare Clarifier" OXPs out there.

Re: [Release] System Features: Rings

Posted: Mon Sep 04, 2017 10:29 am
by RockDoctor
cbr wrote:
Wed Aug 30, 2017 3:23 pm
Colors?
{snip images}
Perhaps this was meant by colored rings :)
As the light from the star passes though the ring material, then the longest wavelength will be scattered first (so, blue scattered light closest to star) leaving an increasingly reddened light at increasing angular distances from the star. Rayleigh scattering, IIRC. Or was it Tyndall? One of those guys with top hats and badger-hiding beards.

Re: [Release] System Features: Rings

Posted: Mon Sep 04, 2017 3:42 pm
by cbr
As the light from the star passes though the ring material, then the longest wavelength will be scattered first
maybe debris of different elements ( different density ) and thus different colours is forming rings of different radii?
maybe not with a monochromatic light source.

Rings of tiny little drops of water/liquid forming rainbows in space

Re: [Release] System Features: Rings

Posted: Tue Sep 05, 2017 12:27 am
by RockDoctor
cbr wrote:
Mon Sep 04, 2017 3:42 pm
As the light from the star passes though the ring material, then the longest wavelength will be scattered first
maybe debris of different elements ( different density ) and thus different colours is forming rings of different radii?
maybe not with a monochromatic light source.

Rings of tiny little drops of water/liquid forming rainbows in space
Nice image. Not realistic. The vapour pressure of water warm enough to be liquid means it would evaporate in seconds. (There is a shudder-making story of a 1960s NASA technician who was exposed to vacuum in an accident while testing space suits in some way. He reported feeling the tears boiling from the surface of his eyes. Now there's a line for the "death cries" OXP !)
Ice bows, on the other pseudopod ... there's an idea. "Sun dogs!"

Different colours of rock - well, it does happen, but it's a pretty subtle effect. The division of asteroids into compositional families relies on such differences, but didn't really get started until improvements in spectroscope technology in the late 1950s/ early 1960s. For the first decade of it's existence, the 200in Mt Palomar "light bucket" couldn't gather enough light to tell the difference in a night's observing.

Isn't there an OXP for an attachment to your ship's comms laser that can tell you the composition of an asteroid? See, even in the Ooniverse, the colours (reflection and/ or fluorescence spectroscopy) of asteroids, splinters and boulders are so subtle that you need some fancy kit to detect it.

On the third pseudopod, there are fair grounds for having a radial variation in grain size in a planet's rings. That's the main reason for the difference in reflection and scattering brightness of Saturn's rings. (IIRC)

Arrgh! I must extrude another pseudopod, then cut it off. The first light from a spectrum to be scattered by (colour neutral) particles is the SHORTEST wavelength (hence Earth's blue skies), not the longest.

Anyone for barbecued pseudopod? Fresh! Still seeping ichor.