Prim Drift?

[Arwen Triellis]

Hi Everyone, I am contructing a build using prims.  Does anyone know why when I link a selection of prims one will go out of alignment?

[animats]

Are you building at a high altitude, several thousand meters up? There is a numeric roundoff problem with high altitudes. Try working near to the ground.

 

[ChinRey]

In addition to the high altitude problem there's also a rotation roundoff issue that can happen even at ground level. If possible, try to choose a root prim with no rotation. If you don't, you may have to correct some of the child prims every time you link or unlink prims to/from the set.

[Wulfie Reanimator]

How significant of a misalignment are we talking about?

[Arwen Triellis]

I am at a high altitude of 3000 is high. That's where my work platform is. The alignment is off just enough to show cracks in a wall. Like for instance. The misaligned prim may be off 90.2999 or something like that instead for 90.000 rotation which throws the x y off also. I have tried unlinking prior to fixing it then relinking but it still goes off again within a minute or two.

[ChinRey]

47 minutes ago, Arwen Triellis said:

I am at a high altitude of 3000 is high. That's where my work platform is. The alignment is off just enough to show cracks in a wall. Like for instance. The misaligned prim may be off 90.2999 or something like that instead for 90.000 rotation which throws the x y off also. I have tried unlinking prior to fixing it then relinking but it still goes off again within a minute or two.

If it's the rotation roundoff issue I mentioned, you have to link first, then adjust.

[Charlotte Bartlett]

Prim Drift, delivering gaps since 2006 (at least)....
The above points are all good ones.  

• Try to keep things sized to rounded numbers e.g. 12.3 Meters versus 12.303939.
• Avoid rotation on the Z Axis where you can especially for the parent prim you link into.
• Plus building / rezzing at height can be painful due to the issues being more pronounced.

It's not just prims, happens to mesh too and can be a total pain as somebody will mod something and suddenly prim drift kicks in when at height etc.

To the point where when I mesh large house elements I often overlap 90 degrees corner planes slightly, so if a mod happens it still hides the drift at least for those parts. 

Edited January 10, 2023 by Charlotte Bartlett
Razzing ha should be rezzing

[Arwen Triellis]

I'm glad I am not the only one to experience this. Unfortunately, I must have a platform that's rather high to build on.  It just seems to be an issue lately. Thanks for the advice!