Prim Float problem

We're doing a whole sim build for a friend. The buildings we are making when done working on one day, when we come back the next day, prims have moved and we have gaps and prims have moved. Anyone else seeing this problem?

Before you do anything, clear your cache, relog, and take another look. What you're seeing could be the result of a cache discrepancy. If the problem persists with the new cache data, read on.

What you're experiencing is called "prim drift". It happens. It's the result of quirk in the math SL uses to calculate object locations.

Here's the best way to deal with it. Shift-drag the offending prims, to leave copies behind, and then delete the originals. Note, the originals are the ones you moved, not the ones that rezzed to occupy their previous locations. Now, move the objects to where they're supposed to be, to close the gaps. With any luck, it won't happen again.

The reason for deleting the original prims, just so you know, is do avoid the much worse form of prim drift, what we call "prim rot". Sometimes after prims have drifted, they become unchangeable. Move them, resize them, rotate them, etc., and they'll spring back after a second or two. Even worse, sometimes they lose their parameters altogether, and end up randomized (wrong size, wrong rotation, in addition to wrong location). Replacing them ASAP after a drift is the most sure way to avoid this potential disaster.

Another option is to put in a rollback ticket, to return the sim to an earlier time. If you're really, really, really lucky, that could be a quick fix. But it's likely the prims will just drift again. The math errors that caused the drift in the first place will still be there. Replacing the prims by hand is a pain, but it's what works best.