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.
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.