I was forging with a guy (name will remain private), and over Xbox Live he was dropping objects on Sandbox and Foundry, and they'd respawn in the air, perfectly interlocked, or floating. And we never ended a round or game, and never stacked. It just kind of happened. I'll get in another video, then get a recording person to put it on youtube so I can link it. I've seen it happen, and he told me it has to do with lag, but the question is: How do you do it? Alright, I got the anwser.
This seems mostl likely impossible. Are you sure he wasn't modding? I'd very much like to see the footage.
I did what I think you're talking about and took a film of it. I recommended it to you but here's the bungie.net link for everyone else. Bungie.net : Halo 3 File Details It's a really old trick actually. It's a hell of a lot easier when not the host. Start a game of forge. Open up the forge menu. Find the item you want to make. Now, this is the hard part. Push A + X really quickly. (Doesn't have to be as fast if you're not host, it's really easy when you're not host.) You should be in the item menu while still holding the item. Push A to build another item, any item. This makes the teardrop for the first item stay where it is, but the object falls, this means when it despawns it will respawn back on the teardrop, which is floating. You may do whatever you like with the second item. Delete it, drop it, wear it on your head. when the other object respawns it will float. You can interlock like this by repeating the trick in nearly the same place before the object respawns.
I get this when lag occurs and I'm not host. This is how the turretless warthog glitch was discovered; try placing a warthog under these conditions. The turret appears after the hog.
Alright, he told me that the way that you said is correct. But I always get host when I try to do this, so I still don't have the hang of it.