Land Impact change: “Is it a prim? Is it a sculpt? It’s a…”

Update May 14th: Speaking at the Simulator User Group meeting on May 1tth (transcript), Falcon Linden confirmed that under the new mesh accounting system, sculpts will be capped at 2: [16:43] Falcon Linden: Namely that sculpts will be capped at 2.0 streaming cost, not 1.0. (Note, that’s a CAP, so if they were less than 2.0 in new accounting before, they’ll still be less than 2.0).

Update May 5th: Nalates carries a very in-depth piece on the proposed Land Impact changes and pathfinding in general, written as a result of recent UG meetings.

Nalates Uirriah caries more on the proposed Land Impact changes which look as if they will be implemented as a part of Pathfinding – and the news carries something of a possible warning.

While the new accounting system promises to offer benefits with regards to prims, and help encourage scripting efficiency within rezzed linksets, just how it will impact sculpties is unclear.

Sculpts have always been something of a problem-in-waiting since their introduction. Like complex prims (tori, etc.), sculpts were given the same “impact” cost as “regular” prims under the old accounting (prim count) system. So wither you rezzed a cube, a torus or  sculpt, they all had an impact of 1. However, like mesh, sculpts are more complex than regular prims and could be said to be somewhat more complex than tori in terms of their download weight due to the need for a texture and a sculpt map to be downloaded and applied to the object.

When Land Impact (initially PE, or Prim Equivalence at the time) was introduced, sculpts continued to be treated as prims – although from comments made at the time, it was evident that, at least on technical grounds, some Linden Lab staff were unhappy with this. However, it is hard to see how the accounting system could have been adjusted to account for the extra “cost” of sculpt without causing mass upset and potentially some breakage across the grid.

The new accounting system that has been proposed, and was revealed in part last week by Falcon Linden as Nalates reported, is specifically to be applied to “legacy prims”.  However, whether sculpts are to be classed as “legacy prims”, it would appear, is still a matter to be determined within the Lab.

Speaking at Monday’s Content Creation Group meeting, Nyx Linden had the following to say on the proposed changes:

The proposed streaming cost cap, if implemented and deployed (nothing is final until it is released), would affect legacy prims – streaming cost of meshes would not be capped. It would affect legacy prims even if they are linked to meshes (and thus fall under the new accounting system). Please note that this is a proposal, and we reserve the right to change any part of it if necessary before release.

“Whether sculpties will be considered “legacy” or not in this context is not 100% determined yet. Since they do require more texture data to display properly, we need to carefully consider exactly how to weight them. The proposed server cost change would be independent of prim type. It’s still in the early stages so bear with us if we end up needing to make tweaks between now and release, but we wanted to let everyone know that changes would be coming.”

After noting that the new accounting process will also be used for linksets using the new physics shape types as well as those containing meshes, Nyx concludes:

“I don’t want to speculate as to the exact status of sculpties under the new streaming cost rules, as we’re still discussing it internally, but your concerns are being considered when looking at the numbers and algorithms.

The problem here of course is that LL are once again in something of a corner. Altering the impact cost of sculpts is going to have potentially far-reaching effects which are unlikely to be seen as positive. It may even negate the changes being made to llVolumeDetect(TRUE), given this hack is often used in linksets involving sculpts. At the same time, and has been pointed out by Chalice Yao, sculpts could be considered tori, so treating them as legacy prims would make the new accounting system even more worthwhile.

Similarly, Qie Niangao points out that currently, the LI calculations are somewhat biased with regards to mesh:

Yes, but on the other hand, the LI calculations are terrifically generous to Mesh content for exactly the reason that Nyx (bizarrely) mentions as a problem with sculpties: extra textures. Although it’s true that a sculpt necessarily involves a sculptmap as well as a (single) surface texture, a single Mesh can have eight 1024×1024 textures and still get a 0.5 land impact.

It is clear that things are in a state of flux – and that LL are considering options and concerns. Overall, the proposed changes are being regarded as being favourable to all at this time where script costs are concerned. Whether this remains the case will be dependent on what – if anything – needs to be changed in order to handle sculpts.

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12 thoughts on “Land Impact change: “Is it a prim? Is it a sculpt? It’s a…”

  1. Let me offer a bottom line. If the end result no matter how you slice it, is less polygons than before, then you get less value for dollar than you used to. Optimizing is one thing, offering less polygons than before means we bear the cost of LL optimizing for the sake of aging hardware.

    Not buying that any optimization whatsoever or perks are being offered to the user, when at the end of the day the polygon math comes out to less. Less is less, more is more. Convoluting the calculations and convincing people that less is more doesn’t make well, less into more.

    Aside from pushing a companies cost on the user and making them feel as if they’re being done favors and that they somehow bear a responsibility to be content creators on a triangle shoe-string budget. Shades of avatar costs. Get the customers to frown on it and buy into “less is more”. If they’re going to offer less triangles, the price tag should also reflect that. Or the hardware should be upgraded to offset less value for the money.

    In the modern world, polygons are not the evil that they used to be and a sim should be able to handle quite a few triangles considering the high price tag. Small mesh with 8 materials on the other hand ….

    But right, my calculator says less triangles means less triangles no matter how it’s spun.


  2. Uh-oh. I foresee trouble. In fact, this is not really a big surprise: we knew that sooner or later LL would wish to get rid of sculpties. Making their Land Impact cost prohibitive will accomplish that overnight.

    But, well, I don’t think this will be peaceful at all, even if sculpties are accounted as torii. The question remains: what will happen to all that content crammed into a 512m2 parcel, now that LI will guarantee that those 117 “prims” are not enough?


    1. Sculpts are very expensive when with land impact calculations (say as part of a mesh linkset) so I don’t see much there to worry about, but if they change a sculpt from being anything other than 1 prim (sorry, LI) in regular content, well that’s going to force a recalculation that could put every home in SL at risk of returns, something I very much doubt the lab has stomach for.


      1. I think that on the subject of “prim equivalence” (one sculpty = one prim), everyone will agree with you; which is why the idea that LL appear to be ring-fencing sculpts in terms of being regarded as prims / “legacy” is causing some head-scratching.


  3. I can help but think this has more to do with the poor uptake of mesh and trying to make it more attractive to content creators, one more tiny benefit add to the already loaded deck of benefits.

    Ignoring all the practical difficulties of learning to make mesh, learning to use a version of blender, learning to use the next version of blender, learning to pirate a copy of maya or max and learning that maybe those hurdles alone are enough to remind you why prims rock.

    Mesh is failing due to context, or more accurately the lack thereof.

    Items built outside of SL and imported in, for want of a better word, just doesn’t mesh. Making mixed mesh and prim content is actually very difficult for this reason.

    This is compounded by mesh not meshing well with other mesh. Go on, you just try and wear mesh shirt and pants from different creators, ignore all the horrible technical problems with avie sizing and deforming for a moment, just try it and stand back. It’s wrong, why? The lighting and baked shadows don’t and wont ever match. Your shirt thinks it’s summer day in june, soft pastal tones and delicate hinting. Your blue jeans were plucked right out of a nightclub .. at 3am .. on a hyper glow dance floor next to a man in a one piece jump suit, a beard like Brain Blessed and one finger pointed to the moon.

    Try and decorate your baked lighting mesh home with baked lighting mesh furniture and Dali himself just twisted your reality. It doesn’t matter how good the individual components are, they will only ever work as just that.

    Yes, so far this is looking more like a poke at baked lighting, but it’s more then that. Lighting simply highlights what happens when items are created out of context. In this case, the context being the broader SL.

    Mesh lends itself to a mismatched uncanny valley at best, and just plain fugly at worst.


  4. @Trinity I never thought about the issue of “baked shadows” on prim-based objects and meshes… you’re so right. So, you think that LL is trying to get rid of prims altogether?

    An artist who is a good friend of mine was literally shocked about this whole mess, since it means that in the future his work and his friends’ work will be utterly constrained by Land Impact — they still prefer to admire each other’s prim torture and sculpty work, since all they take is one prim each. There used to even be competitions to see how complex the sculpture one could do out of a single tortured prim… I remember attending those competitions 🙂


  5. Time to remind them and all that agree, as i do and seems not only Me (tks Trinity to show how mesh is really bad done on Sl and does not work for the purpose all think it should) that there are virtual worlds where land impact is a non existent word, where prim limit can be up to 100.000 and where meshes are used to their main goal, landscaping!
    LL created one of the most amazing things, the prim and if it kills it (what is the object that don’t uses sculpted nowadays?) there is no way but to move to where they cant rule!


  6. I’m never for forcing people to do anything. You can give benefit, but it is better to inform rather than dictate. Yeah, things need to be alot more efficient, and very few in SL ever think in terms of efficiency. They don’t really care if you lag every1, only that you buy their laggy product. But….. if you inform the community of the real issues, and give them the tools to know where the problem are, they will make better decisions, hence making the grid better. As it is, very few in SL understand why things are laggy, nor do they know or understand what they are wearing or rezzing and if it is efficient or not. This needs to be obvious, on the front page of the paper, not buried 3 pages back. LL gives the average user no information, and then has to try and manipulate the system to force people to be efficient. This is not the way to go.

    The bottom line is that mesh is way more efficient than any prim build, and way more than any sculpty build. Even a mesh cube is more efficient than 1 prim. There is no need at all to penalize legacy prims. The only thing that needs to be done is to inform the public. Even if you penalize legacy prims, you are still gonna have 1 million poly meshes. So, all the work and confusion around prim counts is a complete waist of time and energy. If you give the information to the public so that every1 knows how efficient or laggy something is, they will make better decisions with everything, not just old prims.


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