Playing with prims: the new 64m limit

We’re all aware that mesh is chugging down the road in Second Life. What some haven’t twigged to as yet is that with it is coming a new maximum prim size – 64m on a side.

Now, the ability to rez and size prims to beyond 10x10x10 has long been a feature of other grids, and the fact that we’ve not been able to do so within Second Life is simply down to constraints placed on the system by LL rather than any inherent issue with the grid itself. This has traditionally left us with the thorny issue of mega prims, which, as well as being the subject of much heated discussion over the years within the Lab as to whether or not they should be allowed, are saddled with limitations – as anyone who has attempted to stretch a mega will know.

So, what does the new prim size mean for mega prims once it is rolled out? Well, pretty much the same as it does now:

  • Any “legally cut” mega (i.e. those created using the exploit Linden Lab allowed a few years ago when building the likes of Nautilus / Bay City) that are sized within the 64m limit can be safely cut,  tortured and stretched as per a “normal” prim, without it demonstrating any “snap back”
  • Any mega over 64m along any axis can he cut and tortured, but will snap back to 64m when stretched, but can be resized to anything under 64m

Of course, it also calls into the question the need to continue to carry vast stocks of pre-cut megas between 10 and 64m on a side in your inventory (or indeed, within a repository external to your inventory) – which is also to the good.

Overall, the behaviour is pretty much as one would expect, and in some respects nothing to write home about. That megas coming in under the 64m limit can be stretched without snapping back does mean that those who have used them in builds shouldn’t need to go around replacing them all with freshly-rezzed prims if they don’t want to. However, be careful with mega prims created using any skew (usually 0.79) to achieve the final shape, and for some reason these can exhibit a .05 to .1 degree rotation when linked with “regular” prims that have been enlarged.

That said, there are potential benefits to revisiting and revising some builds that use megas. Often it is necessary to compromise in the use of megas and “regular” prims to achieve a desired result. Providing things can be kept to within the 64m limit, this is no longer necessarily the case, as the images below demonstrate.

Built with megas & “regular” prims: 633 prims
Revised with the new prim size: 134 prims recouped

Of course, there are still some limitations – you can’t hollow-out a prim beyond 95% and nanoprims still require a lot of cutting and slicing of small prims, but on the whole, this is a step forward for traditional building in SL. What is a shame is that there doesn’t appear to have been any upward shift in the calculation for determining the maximum prim linking distance.

If you want to have a play with the new prim sizes ahead of the mesh roll-out you can. If you join the Mesh Volunteer Group, you can access the main Grid mesh sandbox area (Surl), which supports the new prim size if you use a suitable Viewer, currently comprising:

Or you can try either the Beta grid mesh sandboxes or, if you know someone on the Main grid who has a sim involved in the Mesh/Live Volunteer project, you could ask them if you could use some space to fiddle with prims.

Objects created using the new maximum prim size *can* be rezzed elsewhere on the Grid – but cannot currently be resized in any Viewer. Regardless of whether or not the Viewer you are using supports the news prim limit, if you attempt to resize a large prim on a non-mesh enabled sim, it will snap back to the 10m limit until such time as mesh is fully rolled-out.

10 thoughts on “Playing with prims: the new 64m limit

  1. Heh… already did a sandbox-and-swap on the roof sculpties for my Clocktree.
    Sized up a bunch of them incrementally, then saw what fit the best.

    This is going to be very, very helpful for tweaks and nips and tucks on megas.



    1. I have to confess, I have not checked ever single “make” of “legal” mega, but Research Project (be wary of any skewed prims), Winter Ventura, Zwagoth (and I unhelpfully forget who else, as I’m not logged in * need to refer to my list) all stood up to the tests OK as things stand – even vying for sandbox space with Dan Linden!


  2. To be honest, I’m much more excited about these bigger prims then the mesh stuff.
    Is there any sort of information on when we can expect these prim sizes to change?


    1. The new max prim size is a part of the overall mesh roll-out; as mentioned in the article, those sims that are currently mesh-enabled on both the Main and Beta grids have the capability, more of the Main grid will get it as the mesh roll-out progresses. If all goes according to the original timeline, the entire grid should fully support the new prim capabilities by the end of August, when the mesh roll-out is scheduled to complete. However, there is a possibility this might slight somewhat given the overall complexities of mesh and its technical impact on the Main grid; so the thing to do is keep an eye on official announcements and commentator’s blogs :).


    1. Is that a work-around, or “official” (as in mesh-enabled) support? Phoenix has a debug override as well but will support “native” big prims on mesh-enabled sims without the debug being active.


      1. The option has been there since a long time already way back before meshes as a feature for other grids where there have been no 10m limit and now it works in SL too.


        1. Disable Build Constraints was introduced purely for OpenSim use.

          However, you are correct inasmuch as it can be used in mesh-enabled sims on SL, and I’ve updated the article.


    2. Maynot matter anyway because the Imprudence project is dead ( He appears to be timing his retirement with the retirement of the V1 based viewers, which can not support MESH.

      My land on Mainland had the functionality this past week (I was surprised when I accidentially resized a prim to 14m and it didn’t snap back). But yesterday lost the functionality. Somone on the Pheonix User Support list also mentioned losing it out on a Homestead.

      I been using Singularity ( to do builds, as V1 code is much faster then any V2 code, but I knew I would have to stay with either Dolphin or RLV V2 once the roll out was done this month. I gave up on Kirsten (I have a ATI card) and Firestorm (No DOF and too many times sudden bugs pop upwith the LL changes).


      1. So far as I’m aware, Jacek is retiring & it is unclear what the rest of the Imprudence / Kokua team will be doing.

        Some 30% of the Main grid is now mesh enabled, with the Le Tigre RC channel being prepped last week and receiving the project roll-out yesterday (10th August). That just leaves the Blue Steel to receive the mesh code on the server-side as far as the RC channels are concerned (The remaining 30% of the Main grid to have mesh comprises the Mesh RC channel, which is presumably tied-in with the recently-closed Mesh/Live Volunteer programme, and the Magnum RC channel), so it is possible Mainland regions have the 64m support now. This is a fluid situation, and with weekly roll-outs, things are in a constant state of change.

        Building speeds on Viewers I think comes down to personal preference and technique. I personally much preferred V1 for building, even after I started using various flavours of V2 official, Kirsten’s, etc.). I’ve now been using Firestorm exclusively for two months, and, admittedly having adjusted some of the way in which I go about building, now find I’m building at least as fast as I managed in Phoenix; indeed, when I *do* change back to Phoenix (so I can use the new prim sizes, for example), I actually find Phoenix cumbersome and slow to use. That’s not to say I think V2 code is in any way “faster” than V1 – but that I now find I’m far more comfortable using it, and as such, it personally suits me better & I can get more done.


Comments are closed.