Ringworld and such

[Pixel]

Do i see a commet with trails in that shot (on front of the Milky Way)?

[marc]

Ive updated the above ringworld it is now in the sol system as well, which should help to view it for a bit longer. It still buggers up celestia though. :(
There is an uninstall.bat which will get rid of it once your finished.

http://sourceforge.net/project/showfile ... e_id=92154

[chris]

Ive updated the above ringworld it is now in the sol system as well, which should help to view it for a bit longer. It still buggers up celestia though.
There is an uninstall.bat which will get rid of it once your finished.

http://sourceforge.net/project/showfile ... e_id=92154

I'll see if I can make this crash on my laptop and figure out what's going on . . . Seems like a nasty bug in Celestia.

--Chris

[Mikeydude750]

Funny, the new ringworld doesn't crash on me. Of course, I'm using MH, not the true Celestia. But I also use the real one. Is that why it doesn't crash?

[marc]

Thanks chris. Im really hoping its something to do with me, and not celestia. Im glad it works for you mikey. Has anyone else tried it?

[JackCrow]

When I first discovered Celestia, one of the first thigns I decided to try was to recreate some of the cooler places in Niven's Known Space, e.g. Jinx:

http://www.windyoaks.com/celestia/Primary&Jinx.jpg

But I knew that Ringworld was beyond me.

Imagine my delight when I discovered marc's Ringworld package.

I've read through this topic, and I noticed and had the same problems that have already been discussed here, but I did I liitle testing to see if I could shed a little light on the topic.

Using v1.2.5, I do have to have both the Sol overlay and the HD 512 overlay in the extras folder in order to approach the HD 125 system without crashing.

But if I turn off Planets in the View Options, I can leave the Sol overlay out, navigate to HD 512, then turn Planets back on once there, and it doesn't crash, nor does it crash after a period of time. I played around in the system for easily 30 minutes without a crash.

http://www.windyoaks.com/celestia/ringworld.jpg

Anyway, I'm just hoping that this may provide some insight as what may be causing the problem.

Celestia is awesome, and keep up the good work

[timcrews]

I just wanted to say that this is a really great idea, something I had not thought of.

I am running it with version 1.2.5 with no crashes at all.

It is interesting that you put it nearly in Earth orbit. In reality, I wonder what gravitational effects the Ringworld would have on Earth in this way? What sort of havoc would this wreak with the moon's orbit?

Are the shadows on the ringworld actually being cast by the shadow blocks? If so, does this count as an "eclipse"? Did you arrange the orbits such that there might be some imaginary "celestial phenomena" involving the shadow squares, earth, and the ringworld? Would the shadow cause square solar ecplipses from Earth's vantage point? Would the shadow of the Earth be visible on the Ringworld? If so, can you give any example coordinates/times that would produce views of these phenomena?

Also, in reality I wonder how bright the sun's reflected light from the Ringworld would be on the night side of the Earth.

Finally, just one aesthetic comment: Isn't there way too much water on the ringworld? I vaguely remember that there were some rivers and seas on the ringworld, but I don't remember continents surrounded by oceans. Of course, cover art is not necessarily authoritative. I don't really remember if the Ringworld Engineers went into any detail on the availability of various elements/compounds that would be required to construct the Ringworld. Is there any possibility of that amount of water being found anywhere in the universe? The surface area of the Ringworld is huge.

Thanks for a great contribution that has made me think interesting thoughts.

Tim Crews

[timcrews]

On the gravity question, I just remembered from my physics class the fact that if you place an object inside a hollow sphere, no matter how massive that sphere is, the net gravitational effect of that sphere is zero in all directions.

I wonder, as long as the Earth and Moon are inside the orbit of the Ringworld, if the same result holds, just in two dimensions instead of three? Intuitively I would say "yes", however I'm not _about_ to revisit the actual calculus involved .

On the other hand, objects _outside_ the orbit of the Ringworld would surely be affected by the mass of the Ringworld. I have sworn an oath never to do calculus again , but I would be interested in knowing the results if anyone else ever decides to figure it out!

Tim Crews

[marc]

But if I turn off Planets in the View Options, I can leave the Sol overlay out, navigate to HD 512, then turn Planets back on once there, and it doesn't crash, nor does it crash after a period of time. I played around in the system for easily 30 minutes without a crash.

Thanks Jack for pointing this out and spending the time to figure it out. I should now be able to make a decent demo script to explore the ringworld.

just one aesthetic comment: Isn't there way too much water on the ringworld?

A big yes to this one, I created this ringworld before i had finished the books. There is too much ocean and the continents are way too large compared to what is in the book. But i think this has a nicer look to it as we would have some troube identifying the smaller features in celestia. Mabey in a later version.

The data i based it on is supposedly pretty scientific. (not just figures picked out of thin air)
http://www.alcyone.com/max/reference/scifi/ringworld.html

Also the earth and moon would most definitly crash into the ring. In the book the ringworld engineers used all the orbiting planets and moons as material for the ringworld. I only put it in the sol system to show perspective and to stop the crashing on approach. That problem is now partially solved.

For those interested the gravity effects will work to some accuracy with the ringworld. Each of the sections has its portion of the ringworlds mass assigned to it.

Anyone got the figures for the puppeteer system? Was it called a quintet ?

[JackCrow]

Anyone got the figures for the puppeteer system? Was it called a quintet ?

I believe Niven referred to it as a Kemplerer rosette, but there were 5 farming worlds, and one world much like Coruscant (i.e., all city), because the puppeteers were herd creatures and liked being overcrowded. So essentially, there were six planets, each one in the two of the others' Trojan/La Grange points.

I think. I may be wrong on the number of planets.

[JackCrow]

I wasn't sure whether to post this here or in Bugs, but seeing as Ringworld is not "canon", I figured here was better than there.

So, I'm zooming around the Ringworld system, and having all sorts of fun, but when I try to zoom out for the big picture, something distracting happens:

Each picture is the result of zomming out one "click" of my mouse wheel.








Why do those white dots show up at the endpoints of the ring sections?

[JackCrow]

And another question:

Why is the upper left quadrant showing more stars than the others? I used F10 to create the JPGs.

[selden]

Jack,

The increase in intensity at the upper left seems to be due to a bug in Celestia which hasn't been located. It happens where any menu windows overlaid the image. It happened on mine for a while and then stopped, so it may be related to the version of graphic drivers. (I'm currently running Detonator v40.72)

One workaround is to run Celestia in a window and drag the "snapshot" menu off to the side before clicking on OK. Alternatively, if your video card supports two displays, you can get a cheap second monitor and drage the window there -- which lets you run Celestia full screen and still take pictures.

Sorry: I dunno about the dots: it could be an effect due to how shadows are cast on that size of an object-- which would be another Celestia bug.

[marc]

Jack,
The dots around the ring are there as celestia treats each ringsection as a planet. In the 'normal' celestia there are not many flat planets around.
Fixing this would require some changes to the source code or it might be as simple as reducing the albedo value (though i cant remember if it is set or not) for each ringsection in the ssc file.

[chris]

Jack,
The dots around the ring are there as celestia treats each ringsection as a planet. In the 'normal' celestia there are not many flat planets around.
Fixing this would require some changes to the source code or it might be as simple as reducing the albedo value (though i cant remember if it is set or not) for each ringsection in the ssc file.

Changing the albedo to zero should indeed eliminate the dot . . . Good suggestion, Marc.

--Chris

[marc]

great, that change will be in the next release.

[JackCrow]

I tried changing the albedo to zero; didn't work.