The Basics of Orbital Construction

Oz Engineering has been investigating the issues and techniques of extremely high altitude activity in the Second Life Universe. Now that the 1.6 conversion is done, and our findings seem to still be valid, we would like to report to the SL community the opening of a new frontier: orbital space.

There are several zones of interest in the SL sky. From ground level to 768 meters is the normal working zone where creation and rezing works and prims, objects and scripts function normally, subject to local permissions. It is within this zone that all aerial constuction in SL is done. A second zone exists from 768 meters to approximaly 4000 meters. Objects created in the lower zone can be lifted into this layer and move about either by dragging or by physical forces. Objects reaching the top of this zone are dropped to lower levels or returned to their owner. Beyond this zone, only avatars using flight augmentation gear and attachments can exist. From 4000 meters up, the rules are different. And new possibilities open up. This is what we call orbital space. And there seems to be an incredable amount of it. One test flight found the outter limit at about 188 thousand meters. At that point the time/space continuum ended. We almost lost the test pilot, but SL tech was able to recover him.

Our tests confirm that objects as attachments can exist and operate in this zone in the same manner they do in lower zones. This creates the possibility of the design and deployment of large and complex structures in this zone, or orbital construction.

Using attachments for construction requires some rethinking of their purpose. They are typically used to modify an avatar's body or as clothing or other personal devices. They are designed to be close to the body and unobtrusive, if not invisable. However, the occasional new resident with a house on his head shows that attachments can be full scale linked objects. Of course, houses were not designed to go on heads, and it look quite out of place. However, objects can be designed to attach to a person at a point in space. And these objects can also be designed to interlock and interact with each other.

As might be expected in a weightless environment, there are some special requirements and limitations with movement. The biggest problem with attachements as structures are that they move with the avatars body movement.. This problem is overcome with a pose that will freeze the avatare into a fixed position. It also must be a pose that stops arm movement while typing. An avatar in such a pose becomes a stable root point for what can be extensive and complex structures. Movement through and around the structure is done by changing and moving the focus, not by surface type body movement. The effect is similar to remote telepresence in a space station.

The possibilities of this kind of orbital engineering are largely unexplored. The basic limiting design requirement is that of the avatar as the root anchor. More than one attached object can be used, up to 40 one for each attachment point, each an element in a larger structure. Each element will need to extend a beam or post to the center of the sphere, the anchor location. This would limit construction to a 30 meter radius sphere surrounding the anchor avatar, or a 60 meter diameter sphere.

There are a number of possible design themes. The structures can be small and compact like a Starwars fighter, similar to the models uses at lower levels, but modified to function as attachments. Larger docking stations are possible, where crafts of various design can dock and join a group at the station in an orbital resort. Another possibility is based on lightweight membrane bubble structures, personalized space pods that people can carry with them into orbit and deploy. Once there, in whatever preferred design, they will be able to navigate in spacial coordinates, find and rendezvous with others in their own orbital attachments and to form ad hoc clusters, orbital space colonies, so to speak

There is still much work that needs to be done to bring this vision to reality. And there are no doubt a weath of possible undiscovered uses of this new space. Opening up this new frontier is a task greater than any one person or group. So I am making this proposal to the SL technical and engineering community to join in resolving the remaining technical issues and to explore the possibilities orbital construction offers.

All of the basic issues in this technology have been tested at orbital levels. It works, but is still crude and unrefined. The remaining technical issues are in the areas of flight instrumentation, navigation and docking manuvering. There are also some side design issues and related projects such as a space elevator project to ferry people to orbit.

I invite discussion from those that might find this an interesting and useful project.


Tommy Oz
Oz Engineering

cool post but aren't attachments phantom? how can you use them for building structures when they're stuck to your body and anybody can pass thru them?

Yes, they are phantoms. But in this environment, that makes no difference. Everybody there is an anchor of their own structure, and not moving around physically anyway. You move with focus point, not body.

I personally have been up to over 500,000 meters and I know somebody who has been above 2 million. It appears that this space will go to float max.

EDIT: At these heights though there are math problems to cope with. SetText no longer works properly and seems to just display jibberish. At higher altitudes like 2 Million the Floating point innaccuracy becomes apparent as Avatars begin stretching like spaghetti.

i'm not trying to be mean but what's the point? if you have a building attached to you and you're not moving.....i guess i don't get it. if you move with focus how does anybody know where you "are"? can't they see you in your attached building or are you inside a "wall"? why not just float around in a space suit or something? i mean what good are the attached structures if nobody including you can do anything with them? and you still have to get within 20 meters of somebody to talk unless you IM and shout at everybody. hehe i'm lost.

Zuzi,

I am not really trying to sell you on these ideas one way or the other. I am simply pointing out some of the things we have found out about about very high altitudes and attachment building techniques .. and the possibilities they present. If they were intended to duplicate the experience at ground level, you're right - there would be little point. But that's not what it does. It is a different environment, with different freedoms and constraints.

Attached sturctures are not simply inert ghosts. They can be quite active, and interactive. Some scripts do not work that are related to rotation and movement in world or local co-ordinates. But physics forces do work, even if the building material itself is not 'physics'. Other wise, the flight augmentation attachements that get you to orbit in the first place would not be possible.

And you are also quite right about the difficulties with finding each other and communication. But solutions to all these problems seems well within the range of the tools available to us in SL. We are jsut begining to experiement with some of these, and still have much to learn. For example, the post above from Dougal is amazing new information.

This is astonishing new information. There have been theories of blackhole like limits to the universe ... could this be direct evidence of that?

This is creating an inversion of our usual self-oriented perspective, most interesting.

Down below in SL and also in RL, we are agents within an external environment. In this outer space of SL, we are the environment, and objects move around with respect to us.

You know what's needed here to go beyond mere camera navigation? Visual telepresence.

Remember the magician's Eye of Zomm from EverQuest, or the Bind Sight spell available to enchanters? This little eye or some targetted mob became the eyes of the character, roaming safely through contorted and dangerous places under normal player navigation controls and revealing their secrets without endangering the real character controlling it.

Well for visual telepresence in this outer space region, we would needs to make roaming attachments, which is doable. However, there is no way (I think) for us to attach our visual perspective to them at the present time. Using them as pivots for camera navigation is not really the same thing, nor very useful. One might as well use the nearest wall as pivot.

So, perhaps we should be calling for a means to assign Mouselook to a particular object!

I can think of numerous fun applications of this down below too. I'd love to experience the perspective of a volleyball during a match.

Movement is always relative. On the surface, it's always relative to the ground, but in orbit, ground reference is meaningless. Things only move relative to each other.





This is interesting. Though I'm not sure how you'd make roaming attachements. Seems movement and rotation script commands are disabled.

What would be the advantage over camara focus navigation, other than the presence of an object at the focal point?

Since the camera heading would follow the position and orientation of the roaming attachment, it would become programmable, and therefore the sky's the limit. Camera focus navigation will always be a manual operation, since the av is the anchor for the spatial environment and does not itself move, normally.

However, now that you mention it, if we can make roaming attachments then we should also be able to make the av itself roam within its attachment space!!!!

This gets a bit hairy, but if you consider an av with only one attachment, this could feature an extensible link arm attaching to the core of the spatial environment, and this core becomes the real hub of that environment in the sense that everything else is attached to it. Then the av will be able to move throughout its captive and phantom environment using a spherical coordinate system, orbitting the hub at variable distances (attached to it by its arm).

The point of the above is that it wouldn't require manual camera navigation to move around the local space, and it would be programmable too, and it wouldn't require LL to extend Mouselook!

Hehe, this is quite wierd.

I tried this kind of a joint to an attachment and could not get it to function. The idea was to program the joint to the root prim that serves at the attachement point to the avatar. It's perhaps best described as a sliding gembol joint that allows both rotation and shifting of relative positions. It does not function because the positional parameters seems to default to those of the avatare.

Do you know how to get that kind of motion relative to the AV?

Not offhand, no. But there's no shortage of building gurus on this forum, let's hope they're reading.

Hmmm, no responses from the building gurus.

Does no attachment with moving parts come to mind at all? Are there no wings that flap?

What about the doors of spaceships moving while we are pilotting them, and hence are attached to them ... could we use this approach instead?

After all, the pilot could be sitting on the door, and thus move through his ship whenever the door is activated --- only minimally in this example though, of course.

It is my understanding at this point that articulated movement in linked structures will not work when attached to an avatar. That is why we had to design around the central fixed point of the avatar as the root of the whole structure.

We do not yet have a complete list of what lsl commands will or will not work with attachements. Except for the articulation related commands, what we have tried does work, including force related and communications related functions.

(Addendum: please forgive my grammar here- I'm hopped up on cold pills, and I'm doing pretty well just speaking a known human language at the moment.)

I've made two high altitude attempts, in order to try and beat the altitudes documented here. Documentation turns out to be the real issue, though. Dougal is right about SetText crapping out after a million meters or so. The first attempt, I used a Cubey Terra Warp Belt, set to take me to 13,000,000 meters. While the attachment became invisible after a few million (wish I had the documentation pics here- not at home), it still functioned fine up until about 9 million. (There's an advertisement for you: "Terra Warp Belts- Good to 9 Million Meters!" By "function" I mean it still took verbal commands, and still showed a jittery white blur for the SetText altitude HUD. However, if you enter mouselook and stare straight down, you can see the HUD well enough to barely make out the altitude setting. Unfortunately, screenshots are nearly useless for capturing this.

On the second attempt, I used the warp belt in addition to three homebrewed scripted "pulse jet" objects to apply several dozen upward impulses per second. This was bundled with a verbal altimeter and speedometer. Using this method, I was able to get decent screen captured documentation up to 5 or 6 million meters before the llSay altitude readouts failed. I *think* I reached around 10 million this time, using the same jittery SetText HUD, before all the attachments stopped working altogether. At that point, I found that my client had frozen, and I had to use CTRL-ALT-DEL to kill it. It's disheartening to log out at ~10 million meters, and log back in falling from 256m, with most of a day's flight gone in an instant. (Incidentally, here's some useful trivia, if you don't already know: person-to-person teleports don't work above 255 meters or so. Same with logout locations. In either case, the av will appear at the correct XY location, but with Z at around 255 meters, and fall to his doom. Useful info for sky platform builders.)

I kind of wonder about the methods used to determine elevation in the above link. It took me most of a day to make these two attempts, one at about 125m/s (according to the Warp Belt's HUD speedometer), the other at speeds in the neighborhood of 200m/s (The warp belt speedometer was rendered useless by the machine gun impulses from the pulse jets- it wasn't designed for these kinds of rapid, short burst speed changes. I had a script to check change in altitude over 10 seconds for speed calcs, and even that varied by +/-10m/s). I have reason to believe that 250m/s is the game maximum speed, at least in the Z-axis (shorter term speed checks in preperation for the second attempt sometimes jumped that high for brief periods, but never higher). At that speed, it'd take 13.3 hours to hit the claimed 12 million. It would take DAYS to travel it at unenhanced flight speeds. Keep this in mind when designing an orbital. Is anyone going to be willing to invest a half hour or more to visit you at 500km?

My point in this long digression is this: just about every aspect of the avatar and of objects in general gets exceedingly weird at only a couple hundred thousand meters. SetText stops working reliably, drifting downward, and jumping up and down. Sounds- both from game menus and from your own WAV samples- become distorted. Your avatar starts stretching and jittering. This gets worse with increased altitude, until all the attachments become invisible and your avatar becomes an odd collection of stacked plates in a rough human shape, with outstretched arms occasionally growing spikes or bending in troughs in no discernable pattern. You probably won't be able to do much useful building above the mid 6 digit altitude range.

I think I've got to agree with Zuzi on this one. What is the point of this? Is it better to have buildings attached to you at 6000 meters than at a more normal, though still high, height of, say, 300 meters? I can't see many benefits in going higher. And, what can you do with prims that are attached to you? I can see a bunch of people making a "building," but it seems rather useless since it is non-physical, and so all you could do is move your camera through it. Camera controls aren't even well-suited for this, since they are relative to whatever they are focused on. It would be hard to move the camera around. You can't really do anything up there, and you certainly only limit the possibilities of what you can do when you go that high. By going to 6000 meters, you don't gain any benefits over a lower altitude, and only lose practicality.

Summary: That's wonderful! Now, when you show me something that you can only do at extremely high altitude, I will actually be impressed.

I've also been over 2,000,000m high in second life and some very strange things do indeed happen......
http://slconceptual.wordpress.com/2007/05/05/weird-things-happen-when-you-get-high-in-second-life/

I'd also pondered on the possibilities of wearable buildings (strictly speaking dance floors)
until I came up against the phantom attachment problem. It would have made a great camping chair - someone prepared to carry a whole dancefloor for 2$ for 10 minutes.

I'd also contemplated the possibilities of a simulated zero-g environmemt, but best not dwell on those in a family forum.

The idea is intriguing though - I may do some experimenting of my own.

That's nice and all but you necroposted. Please, look at the date before you post if its older than three months, its most likely inaccurate, or the posters gone.

Hello,

Thru flight assist attachment I also have been up to 150 mill in altitude. I have a pic of myself at Sun level (Its not above me but perpindular to me) and I nicknamed the pic "Icarus".

It seems to me that while a physical structure attached to an avatar would not be useful as a physical dwelling or I.E. something to stand on up there, I can see a volunteer or an alt perhaps being used or submited as an anchor to a structure that others can visit or use for orientation, in a sense a "cyborg station". Said alt or voluteer would be there for extended times and commited as a waypoint for other travelers. I think each traveler as has been mentioned would have need for their own exploration medium I.E. space suit, space bubble exetera.

I think it would be notably interesting to see at what height limit we could utilize a functional "dance ball" and also if streaming music can be heard at this height as an orbital night club may be the coolest venue for people to meet in this enviroment.

This is a new realm for explorers and redefines us in the same way that deep sea life redifines our concept of existance. I salute the efforts of anyone persuing this!

Good job and great post!