What EXACTLY is a Megaprim?

Hi guys,

What exactly is a megaprim. I know where to buy them, but can someone answer these questions:

a) How can I make one?

b) What advantages, if any, do they have over regular prims?

c) Can I treat a megaprim in exactly the same way as regular prims, or do megaprims have any health warnings?

d) Is there any maximum limit to the size of megaprims?

Rock

Hiya Rock,

Megaprims were made a long time ago when SL was young and innocent. You can't make any more; you can only buy them now. Linden Lab has said that it's going to get rid of most of the ultra huge megaprims, but will let us keep the ones around 20 meters in size.

They're advantageous in building if you want to keep your prim count low, but keep in mind that they can have adverse affects on sim physics. It's hard to rez objects on a megaprim, for instance. I'd use them sparingly.

The largest megaprim I've ever seen is the size of a whole sim, but those are definitely a bad idea and will probably get removed by LL if it knows that you're using them.

a) no. These prims were created via a hack by Gene Replacement (aka Plastic Duck) who is another story all together.

b) they can cover a large area that used to use dozens of prims with a single prim. The most widely used is the 20x20.

c) use at your own risk. The smaller ones are mostly safe. The larger can crash sims, piss people off and are frequently used as a griefing tool.

d) the largest is about the size of an entire sim.

a) you can't. See above. They were an exploit in a broken client.

b) they're really big and allow really big builds

c) no, and yes. No, you can't treat then exactly like regular prims, and yes, there's health warnings.
-some have a larger actual size than viewable and can cause encroachment issues
-they always have the same impact zone as when first rezzed. if path cut or hollowed, you can't walk through the invisible bits.
-NEVER EVER EVER EVER make a megaprim physical. This can cause anything from minor collision issues to sim-crash.

d) megaprim size limits are stuck with what we already have. What you see is what you get.

They are prims created using an old exploit. Once, long ago, the server didn't check the sizes the client told it the user had resized a prim to; the limit was enforced by the client. Someone used this to manipulate the information sent to the server, creating a selection of prims larger than was supposed to be.

You cannot make them anymore; only get copies of the original ones. (They are circulated freely; paying for them is a rip-off).

The advantage is that you can save prims on things like large walls, building them from one mega, rather than a lot of smaller ones.

People disagree on the dangers. Turning them physical is documented a bad idea, and hollow does not work correctly on them. Using megaprims larger than a sim is also not a good idea.
Also, many of the megas you see are in reality path-cut and/or dimpled versions of the base megas, so their "footprint", the size registered in the landscape, is considerably larger than their visible size.
Similarly, they can be hard to rez things upon, since the server is confused about where the surface actually is.

Whether the large (but less than sim-size) ones are actually dangerous is up in the air. There are lots of circumstantial evidence and anecdotes, but no good technical explanation why they should be any more dangerous than the smaller, but still larger-than-10-meter megas. (The 10 meter limit is a part of the physics engine, so it would stand to reason that you're either above that, or not).

Using some of the more reasonably sized, and setting them phantom if at all possible, seems to be an acceptable way of using megas, both socially and technically, though, as said, people's opinion on them vary wildly, and LL is looking at possibly removing (some of) them with the upcoming Havok update.

Megaprims can, to my knowledge, be up to 65536 meters, though I don't know if that was just made as a convenient multiplier of the sim size. They *can* be larger than a sim, but rezzing one of *those* is likely a ticket to ban-land.

Oh, and one obvious point that nobody has mentioned:
Megaprims cannot be resized normally at all. If you need a size other than the existing ones, you have to path-cut/dimple one, "faking" the size that way.