OHM O'Neill Island 3 Colony v0.9

[OrbitHangar]

Author: frogisis

A 50km long rotating space colony, designed to be placed at the five Earth/Moon Lagrange points.

...Unfortunately that turned out to be beyond my scenario-programming ability, so I've put five of them in wide orbits around the Earth and the Moon, to give about the same impression.

Perfect for adding a sense of advanced civilization to your scenarios, or giving yourself a destination beyond the ordinary station or base.  The source code is included in case anyone wants to improve or redesign it.

Many thanks to Ursus on Orbiter Forum for help with the C++ and getting the gravity drum to rotate.

<<UPDATE>>
 
Thanks to ajaja's wonderful and intuitive Lagrange MFD just made available on Orbit Hangar (http://www.orbithangar.com/searchid.php?ID=4582 ), the colonies are now in their proper positions. 
You should download this MFD A) because it's useful in general and B) while some playing with time acceleration shows the colonies will stay in position long enough for the purposes of a few flights around the Earth/Moon system, if they begin to drift, you can shift focus into them and use the "GO" button on the MFD to zap them back where they belong.  Thanks, ajaja! 

Happy flying!

DOWNLOAD

 

[Ark]

That's actually pretty cool, even with the mesh flicker. Dunno what to do about it, though.

 

[stevcast]

Well done, and very interesting visuals.

 

[eveningsky339]

Does anyone have enough knowledge of the L points to put the station at a proper Lagrangian point? I've been tinkering around with L points for quite a while, but I'm just not knowledgable enough to do it.

 

[silent_protagonist]

There's a default scenario in Orbiter (under Navigation->Special Orbits) that puts a DG at Earth-Moon L4, which might be helpful.

 

[Frogisis]

A useful tool just popped up on Orbit Hangar that let me put the colonies where they belong. Updated and uploaded the scenarios in the zip file, and they should be ready for flying.

 

[Izack]

Apparently Island Three is composed of two attached cylinders, not just one.
http://upload.wikimedia.org/wikipedia/commons/1/16/Spacecolony1.jpg
In this image, if you look closely there is pair of angled struts between the two habitats. Also, there is another pair in the background, suggesting they are also attached.
According to the Wikipedia entry, the two habitats would be rotated at slightly different rates, causing them to precess enough to continually point their mirrors towards the Sun (It's also worth mentioning now that those mirrors must point at the Sun). Also, attitude control might be nice. I'll see if I can look into that for my own Orbiter, as you are done development.

Nonetheless, since I started playing Orbiter I've wanted O'Neill habitats, and you've done a fantastic job making them. Very nice looking on the inside and out, despite their size. Thanks!

 

[Keatah]

Space colonies totally rock. This is good.

 

[126er116]

no textures

Can anyone help me? When I run the scenario, non of the colonies show up. The delta glider is there, but all of the colonies are only one pixel. I tried different zoom settings and restarting my computer, but nothing worked. Does anyone have any ideas?

Thanks, Patrick

 

[Frogisis]

Disabling vertical sync seemed to help a little bit with the mesh flicker for me, so that could be something to try, but otherwise I couldn't begin to guess...

@Izack - I originally thought about having the colonies be doubled-up, but decided for framerate and playability reasons to have them as singular objects. I think it looks a little more dramatic that way, too, but your're right about them ideally being paired together.

Does anyone have any idea why the mesh flickers at different distances like that? I've never been able to get the Death Star addons to work so I'm not sure if this is a universal problem for large objects, or something specific to how this one is rendered.

 

[MVA]

Great addon!

 

[Izack]

Just tested in Orbiter 2010. The flickering is much, much worse.

 

[Aldrasio]

There is quite a bit of flickering, but this thing is so awesome I find it hard to notice.

 

[JonnyBGoode]

When I use to make add-ons for Half-Life, flickering like that usually meant that the planes of two mesh objects were on top of each other, existing in the same space, and the graphic engine was trying to render the textures of both at the same time.

Example: Here is an edge-on view of two rectangular solids. The third dimension is parallel with the viewer's site, i.e. you're looking at that dimension edge-on.

The section circled in red is where the faces of these two solids occupy the same space. In that area, the rendering will flicker as the graphic engine tries to display both faces simultaneously. Removing one of the faces in that area (i.e. cutting a hole in one of the solids in that region) will solve the problem.

At least, that was how things worked when constructing Half-Life buildings and objects. I'm fairly sure the same would hold true here, but I can't say for 100% certainty since I've not tried to construct anything quite so massive.

 

[Frogisis]

I was wondering if it wasn't something like that... I hoped it wasn't, though, since I've had to reinstall my OS a couple times since I made that model and am pretty sure if I were to fix it I'd basically just have to start from scratch, something I have neither the time nor motivation to do...

I'll have to come up with some kind of other addon one of these days to make up for it.

 

[Izack]

If that were the case, then why is it that it only happens when the camera is far enough away to display the entire object, and only on extremely large objects? I can think of at least several addons more poorly made than this (not that this is poorly made at all! Just a matter of wording...) which don't experience the same problem. :shrug:

 

[Frogisis]

When I was making the model I made sure there were no "coplanar," for lack of a better word, faces, but a lot of them -are- pretty close together since that was the only economical way I could think of to have different textures on two sides of a thin object.
...Maybe when the camera distance is some multiple of the distance between the polygons they start to flicker? Really, I couldn't begin to guess what's causing it, but if it's the only addon that seems to have this problem, maybe it'll at least be a way to find some new hangup in the Orbiter core or some other minefield addon makers might have missed.
It doesn't make the colonies unusable for me, since they only flicker at two specific ranges on my machine, but yeah, it's annoying as hell and really makes the addon feel unfinished.

 

[JonnyBGoode]

Well that was my best guess... otherwise I have no idea.

 

[Izack]

A simple test might be to try this with the same model minus the textures, to see if the mesh faces flicker. Not sure how one would go about that, though.

 

[n72.75]

It's called Z-fighting. Here's the Wikipedia article: http://en.wikipedia.org/wiki/Z-fighting