Physical vehicles with Mega Prims

I want to make a physical vehicle using a 100 x 100 x 100 sculpted sphere. Would there be any problems in doing this? Are there any scripts that would allow this to be done?

any vehicle script should work.... but I don't suggest it.

1) that's huge, almost half a sim huge, vehicles are notorious for having issues on sim crossings

2) if you come into contact with ANYTHING the sim physics engine is going to grind on this horrible because of the huge bounding box... heck it may grind even if you don't

3) assuming someone notices 2, you could be AR'd. last I rmemeber even the Lindens that were fond of megas say NO to megas + physics. it could very well be considered griefing.

you could look for one of the many non-physical vehicle (NPV) scripts... these are bound to be a lot more sim friendly in this case.

what kind of vehicle would you make with such a large sphere anyhow?

The Death Star?

sculpty, could be anything.... although the Hindenburg would be a great example =X

Void,
Where can I find the Linden information regarding mega prims and physics? I sure don't want anything to think my creation is griefing.

I've been playing a little with the mega sphere and my airship sculpt on the test server. I found I can link everthing so far, by moving it close then edit linked parts and move them where they should go, but it seems they will not move and stay, more then 1/2 the sphere or 50 meters. They will move themselves back to a comfortable position they like. Is there a way to get everything linked and moved the entire length. I still would need to make the back parts of the airship and link them.

Another thing I found is that the sculpt acts likes it's phantom, but it's not. So once you link, everything acts phantom. This could be good, not causing problems bumping into anything, but then you can't stand up and walk around in it.

I have considered using the multimove script but I've been on a few ships and seen now they move..it's not pretty. It would ruin the effect of the slow smooth movement the airship should have.

I just had a thought...what about temprezing the mega sculpt around the physical base? Is there any way you can attach a temp rezzed prim to the base or you avatar?

Ruthven,
It is a long steampunk style airship....well, I was hoping it would be. I always seem to come up with ideas SL does not like or won't let you do

I may end up just making it smaller or just a skybox

the Linden "offically posted in the blog" policy is " mega prims are ok as long as they aren't causing problems for other users". the more specific instances I've paraphrased are from various forum threads that lindens participated in (a major one was in building tips, a thread about megas, which I belive it was andrew Linden that posted in it, around the low 40's)

I don't know why your mega sculpty is acting as if it's phantom, unless there was maybe a change to the server code in how vehicles in megas are handled. or perhaps ithe sculpt shape is offset from it's bounding box. even if it weren't, standing would only be in places where the bounding box was, not the surface of the sculpty. I do know that as an attachment it's definately going to be phantom, and may have some sever limits on how far it can be offset from the attached av (never checked the max for those)

as for why your linked objects are snapping back? it's because of link distance rules (which are complex and a headache) which refuse to allow links past a certain distance (pretty much the reason multi-move was created).

you might cheat and be able to apply multimove or something similar to just 2 pieces, the larger sculpty, and the deck etc, and not have it look clunky or disjointed. beware of llRegionSay if the current version uses that, because it can all got hell if you try to cross a sim border.

It's not a vehicle yet..no scripts, but I didn't think to check the bounding box. I'll take a look at it next time to do some more testing. I would think it should still be in the bounding box. The scuplt is using a 100x100x100 sphere. The shape of it is long and narrow..about 30 meters diameter in the middle and 100 meters long.

When I rezzed the mega prim as a normal prim it was solid. You could stand on it and in it but you have to get in by rezzing it on you or rez a prim, sit on it and move it inside. I haven't played with large sculties before and just assumed when a prim became a scuplty, it acted phantom.

The prims snapping back is a major hinderence on making this ship that big. I did some further testing on 10x10x10 prims and it seems the move limit is a little less than 50 meters.

How would you use the mutli move and a physical script at the same time?

I think I will have to make it 50 meters long at the most in order to link everthing for a vehicle. As a sky box, everything won't have to be linked together. I think a rezzer will be needed tho...something you sit on and take to the height you want and it rezzes at that height, like the Builders Sky box.

If you do decide to go the rezzer route then take a look at these scripts:

http://wiki.secondlife.com/wiki/Multi_Item_Rezzer

Works like a Paradise Blanket with the ability to add your on objects and set your own target heights.

this might help on your link distance problem (or just confuse you further)... I'm not sure if cuts affect link distances or not. https://wiki.secondlife.com/wiki/Linkability_Rules

as for multimove and physical vehicles, I would think you'd treat it just the same, using the vehicle base (which will be limited to 32 prims - seated avs) essntially the vehicle tells all the other unconnected parts when it moved, and where to. for a slow ship it might only barely register differences in movement between them(in fact if the vehicle is hidden in the ship it might work even better, although the driver may bounce around a bit.) shout is 100m and crosses sim borders so should be workable.

the phantom problem is a bit weird, and the only thing I can think is that maybe your already inside of the sphere when you try to stand on the sculpt surface which would cause you to fall through and not be able to go back up through it once you passed the sphere boundaries.

I have a few physical vehicle designs that use smaller megas (20x20x30) for dirigible envelopes and such, and in testing them have observed no ill effects. Even when playing "bumpercars" in a clear sandbox with three others, the info display showed no difference than the same activity in the same vehicle sans the mega prim.

Admittedly, this is a single, smaller mega as part of a slow vehicle.

A sculpted 100^3 maybe another matter. However, I would think that you could use the Phantom Child trick to remove it from the physics equations. http://wiki.secondlife.com/wiki/Phantom_Child though I have never tested it myself.

Maybe the 2 prim sculpted Hindenburg should be born as a test vehicle.

I added the reset on sim restart code to the changed event for the referenced script just now for anyone that wants to use it in permanent structures.

Thanks for the links

The info on the linking rules helps to understand the limits. I did some further testing with 50 mtr spheres. You can link 2 of them together, but they are with in each other by about 1/2. You can link a third sphere, but no more. I'm not sure how I could use this in the build.

I also tried some various sculpts I have and they all seem to have a solid surface. I don't know why my sculpt of the airship shape with a 100 x 100 x 100 sphere acts phantom. I tried it a 50 x 50 x 50 and it is solid, but the I can't actually stand on the surface of the sculpt, it seems I can only stand on the bounding box limits. It might have something to do with the way it is rendered in Blender, but I don't know what it would be. This testing was done on the test server. I don't seem to have my other set of recently aquired mega prims in the inventory there, which may be the ones I will actually use.

Void,
I got the phantom child script from Wiki and tried it, but I get an error on line (19,33) : ERROR : Name not definded within scope. I don't know enough about scripting to fix it. Do you think you could take a look at it and get it working?

yeah we had the same problem in the other thread, I'm going to revert that change for the moment, because at the very least the constant isn't in the compiler... it MAY be that the CHANGED_REGION_START return isn't even isn't even live on the grid yet, and somehow the wiki got messed up to say that it is... but if it is live on the grid (and somebody just forgot to add the constant to the compiler) then replacing the constant with 0x400 should work... I can't test though as I have no way to reset a sim.

making that suggested change will make the code compile, and shouldn't affect anything if the code isn't live on the server (if it is then the change will make it work)