Prims in linkset shifts

[TrudyMarie]

I am working on a house, and when I create linksets, a prim looks like it shifts, I unlink it and it shifts back, is this a bug or am I doing something wrong? The linksets consists of 64m prims so I am using the sl build tools, number of prims within the linksets are approx. 8 prims, however, none of the prims in any of the rooms shift, it's just the balcony. 

[Rolig Loon]

When you build that high in the sky, all bets are off.  SL gets really wonky up there.

[Lindal Kidd]

I think Rolig nailed it.  The build limit is 4096m.  With its center at 4051m, your 64m prim may very well be running up against that limit.

[TrudyMarie]

Ok so it's due to the height of my build platform? I will lower it and see if that helps and let you know.

[Rolig Loon]

I don't know whether anyone has done an accurate study to find out how high you can go before drift gets as noticeable as you are reporting.  The closer you get to the maximum building height, though, the more you will experience prim drift and other odd phenomena, so it's best not to push it.  It really shouldn't matter whether you live at 4000m or 3500m.  You won't get many visitors up there at either height, but your building will behave better at the lower altitude.  So will teleports and some other features. 

[TrudyMarie]

It's a private home, and i am rebuilding it as a surprise for my guy, i would build on ground level but as I mentioned I want the rebuild to be a surprise. I dropped my platform down to 1000m and will see how the prim drift is.

[TrudyMarie]

Thank you, that seemed to have fixed the prim drift

[Lindal Kidd]

It might be prim drift, but I don't think so.  We did some high altitude building tests a little while back.  When any part of a prim is placed above the max building altitude, 4096m, the prim snaps back to an allowed altitude.

[Nalates Urriah]

Yeah... 'prim drift' is an over time thing. Not something you see in a day or two much less with a single click.

There are posts here about how to deal with high altitude building and preventing prim drift.

[Pamela Galli]

When I build a house at 1000m, some prims will drift if I rez at ground level. I have to ride the house down to avoid that.

[TrudyMarie]

I am just above ground level, about 50 meters, and I am still getting prim drift, I have searched the archives and tried the various fixes, even locking the prims but they still shift when I go to link them, I then have to go into edit and readjust almost every prim. 

[Rolig Loon]

5 hours ago, TrudyMarie said:

they still shift when I go to link them

I don't understand.  Do you mean that if you left them unlinked, they would not drift?  They only "drift" in the instant when you try to link them? And later, when you have adjusted them in the linked object, they do not drift again?

[TrudyMarie]

Mostly correct, if I link 2 or more linksets together all the prims shift, if I link one prim at a time, I always have to readjust the prim I just linked, sometimes 5 or 6 times before it sticks, if I accidentally select the single prim last making it the root prim, all the prims shift.

[Lindal Kidd]

Trudy, all the talk about high altitude is based on the picture you posted, which shows you are at 4062 m.  If you are still seeing this near ground level, it's got to be something else.  Are you near a parcel border?  I dunno...maybe it could have something to do with how your snap options are set??  I'm reaching.

[Nalates Urriah]

Once you are below 4km the math isn't a problem. Above 4096m the binary nature of precision being used forces least significant digits to be dropped. You can dig into the math used to run SL in the wiki. 

DRIFT... as I said above, drift is something that happens over time. It is more like an hour hand moving. It also happens when regions restart. It sounds like you are describing prims snapping to slightly different positions. But, how much are they moving?

The position of things in-world is a combination of viewer and server information. During editing the viewer updates the server on where things are. The server updates others on where you have moved things during editing and updates your viewer on where things are. This allows us to do cooperative building as part of a team in real time. I have never needed to know the precise timing of those updates. But, I have seen prims move around during editing when the server and viewer get out of sync. I tend to see it most often when adjusting prim attachments to the avatar in a busy region.

The server-viewer communication on movement is via the UDP protocol. Packets can be lost. Servers get busy and can get behind on updates. Thus we have the infamous rubberbanding. Things get out of sync and then some clicks force an update or during editing the delays used to reduce network traffic time out and server position updates overriding the viewer.

So, check the server and connection performance using the Viewer Statistics panel. (Ctrl-Shift-1 toggle) Make sure your Max Bandwidth in Preferences is no more than 1,500. If it is at 1,500 reduce it by 500 and try again. Then to 500 and try again. Watch packet loss. 1% loss is high. Ping times greater than 250ms can be a problem.

The Packet Loss numbers given in the Stats panel are a running average. So, the 0.0% is less and less precise the longer you are on. Time pushes it lower. Also, the login process distorts the number pushing it higher. But, a display of 0.0% should mean you are OK. 

Try a region like BlueSteel Sandbox 1. OR any deserted region.

Which viewer are you using?  It may help us figure out what is up if you provide your viewer-computer specs. Help->About... Also, the rated speed of your connection.

Edited June 29, 2018 by Nalates Urriah
corrected mistake

[TrudyMarie]

I use firestorm, and I dropped down to 60 meters, there is still some drift, anywhere from .001 to .01 meters, or the prims will rotate anywhere from .001 to .1 degrees. This is even after I have got them set perfectly, put the rezzer script in the root prim, lock the section, and then put it in the rezzer. When I test rez it, many of the prims will either drift or rotate, leaving visible gaps. I want to sell my build but I am a perfectionist and dont want to sell them if not perfectly aligned.

Edited July 2, 2018 by TrudyMarie
Mispelling of a word

[Nalates Urriah]

Are you lining everything up along the X,W,Z axis? If you are working at angles, you are going to have round off issues in the X,Y,Z values. While you can build aligned to the grid and avoid shift while building, customers will likely rotate the building. I don't know that it is possible to avoid that type of prim shift. But, these shifts should be small and mostly invisible until you zoom in.

How big are the prims? If you are trying to get large prims to fit together, you have to keep the dimensions to even numbers so they will fit together. Otherwise, odd dimensions push you to tweak the locations away from symmetry to get precise fit. 

Perfection inside a digital world has limits. In general movement of 0.0001 is invisible. Separations between prims of 0.0001 is invisible. However, a shift of 0.001 is very visible.

Shifts of 0.01 are huge. Shifts of this magnitude one sees when they make things Physical. So far, the only way I can get prims to shift out of the position I put them in is to have one of the prims set to Physical and then link a non-physical prim, which then becomes physical too.

So, if none of this helps, I would need to see it in-world.

[TrudyMarie]

I am lining up on the x,y,z axis, they are all non-physical prims, I noticed that it is mainly the window frame prims that drift, occasionally a wall will, but I will put a notecard in with instructions on how the fix any drift the buyer may see. 

[Dekka Raymaker]

I have been building in Second Life for a long time. When the prims are linked check the rotation boxes, you are likely to find that the prim has twisted, rather than moved, usually by a minor degree. When unlinked, it untwists, i.e. the rotation fields go back to 0.0, 90.0 or whatever they should be. The only solution I have found is that once the build is in it's final position, just unlink and everything will be dandy.

[ellestones]

15 minutes ago, Dekka Raymaker said:

I have been building in Second Life for a long time. When the prims are linked check the rotation boxes, you are likely to find that the prim has twisted, rather than moved, usually by a minor degree. When unlinked, it untwists, i.e. the rotation fields go back to 0.0, 90.0 or whatever they should be. The only solution I have found is that once the build is in it's final position, just unlink and everything will be dandy.

agree

i notice that its more prevalent when prims that could be oriented similarly are not. For example <0,0,0> and <180,0,0> in the same wall, etc. The other thing that tends to disrupt is when the root is a totured prim rather than a non-tortured prim and the linkset is then set to convex