A little confused this is not a bug?

[Gearsawe Stonecutter]

CTS-647

I am a little confused. This is not a bug? Depending what is the root prim a normal prim or mesh the cost can be 2 or some bizzard high number???

[Nyx Linden]

Any prim in a linkset with a mesh or a prim that uses a non-default physics shape type will be evaluated according to the metric "weights" (Download, Server, and Physics). Whether a primitive object should be evaluated with the old system (a prim is a prim), or based on its qualities is determined at the linkset/object level, not at the individual primitive level.

 

See http://community.secondlife.com/t5/Mesh/Calculating-quot-Prim-Equivalency-quot/td-p/937343

 

We hope to get the wiki documentation up to date on this matter soon, keep an eye on https://wiki.secondlife.com/wiki/Mesh/Costs_and_fees

[Gearsawe Stonecutter]

well I guess we cannot mix normal prims and mesh now in the same link set.

I can now take up all sim prim resources with 298 torus and 2 box mesh. What is the sense in that?

Better yet When I link the prims together they get returned. then I cannot them again rez becasue the set is to large to rez unless I find a completely empty sim. 

By putting in so many limits you keep making horrible flaws!

[Drongle McMahon]

Here are some observations I made concerning these matters. Some notes, but also I can't see the relationship between PE and either streaming cost or display cost. I would be grateful for any light anyone can shed on this.

[Nyx Linden]

Nice chart!

Display weight is currently a highly inaccurate algorithm and has no impact on the prim equivalency.

PE should be displayed if it differs from the prim count (thus is not redundant information). Number 5 definitely sounds like a bug to me!

[Drongle McMahon]

"PE should be displayed if it differs from the prim count"

Oh. That would explain it then. The PE for the whole linkset is shown when you check edit-linked, and that is 5 for the linkset with the mesh cube as root. That is the same as the prim count. The question is then why PE is 5 there when it's 158 with a prim screw as the root. Maybe that is the bug? I'm going to recheck it.

 

[Nyx Linden]

There's at least one instance of incorrect PE numbers being displayed - see https://jira.secondlife.com/browse/CTS-643

If there are more instances where the wrong values are displayed, definitely let us know!

[Drongle McMahon]

By the way, I think it would be substantially less confusing if the PE was always displayed for mes-containg linksets, even if it's the same as the prim count. In fact I see no harm in displaying it for standard prim/sculpty linksets too. It's much better to have one consistent place to look for the amount of prim allowance the object will account for.

[Nyx Linden]

That would be a fairly trivial code change, I can bring up the possibility with our UI designer.

[arton Rotaru]

I'm  thinking about the average Resident, who wants to link his torus to a mesh building block or something, and BOING, 3586 prim object is born, just by linking a 12 Triangles mesh cube and a legacy twisted torus prim. :matte-motes-nerdy:

But I suspect that's what they try to achieve in the long run, deprecate expensive legacy prims as time goes by.

[Drongle McMahon]

Think of the hair seller who puts his 200 torus hair on a nice mesh manekin head fo display.... might as well link them....BANG.... whole store returmed in random pieces.

[arton Rotaru]

Yeah, it's insane.

[Gearsawe Stonecutter]

Yes we might have a problem. After this gets returned can't rez it anywhere. PE 23994??? BTW it is linked to a mesh box

[Nyx Linden]

Interesting thing is, it *is* actually that much more complex to our physics engine. We do full simulation of a shape very close to the render shape for regular prims, and in the case of sufficiently convoluted torii, its a bit of an issue to say the least.

Could you try setting the torus' physics shape type to convex hull and see what effect that has on the reported cost?

Any suggestions on how to clarify how the new system works and/or how to get the word out to inform builders before they run into the "gotchas" would be greatly appreciated

[Drongle McMahon]

Nyx. I think it's not just builders you have to worry about. There are any number of scenaios where a resident might very reasonably decide to link normal prims to meshes with disastrous effect. The example that occured to me was someone selling a nic mesh mannekin, and a user deciding to put their spare hair on it. If that is the typical 200 small toruses and they decide to link them.... Then there's the house with sculpty windowframes whose owner decides to link on a nice new mesh chimney pot .... etc.

 

[Gearsawe Stonecutter]

Yes this will all be a rather confusing high learning curve for the average resident. For me I will have to now use more scripts since I cannot link a mesh to normal prims becasue it can inflate prim cost. Before I could keep things as one linkset and one script. Now it gets a little more complex with listerns and such.

Everytime a limitation has been added in SL usually means it takes more resources to do the same thing than it would if there were no limits at all. Therefore having the oppsite effect of ithe imposed limitation.

[Psistorm Voxel]

I fully agree with Drongle. There are just too many volatile cases here where linking two objects together suddenly creates something that is greater than the sum of its parts. I do NOT want to live in the constant fear of having my home be returned to me just because I link a 100 triangle mesh to it and that caused the entire thing to go haywire.

I would like to direct you, Nyx, to the thread i posted lately to address some of these concerns - not all of them, but i certainly tried - and see your opinion:

http://community.secondlife.com/t5/Mesh/A-draft-to-end-PEwt-discussions-The-resource-point-system/td-p/945759

Yes i know its a bit of a plug, but i would love some linden feedbakc on what I think is a good idea. On the issue of builds being returned specifically i would like to suggest to make a "is parcel full?" check BEFORE executing the link. So that if you do one of those volatile linking operations, the viewer blocks you from it with a warning, rather than returning your house or whatnot without warning.

 

Edit: I would like to go a little further on the issue of this topic and say the following: In light of usability, and the "your world, your imagination" phrase that seems to be SL´s guideline in design, i believe that the mere idea of a linkset being 1000x heavier weight - or a different weight at all - than the sum of its parts is indiscutable and should be discarded.

There have to be solutions to fix the sudden explosion of physics complexity, and there has to be a way to create a transition to an all-encompassing, easier to understand system if you decide to add these weightings. I again briefly point to my suggestions above to the nature of the system, but for the problem at hand, my stance remains. Just because you link two things one way or another, their cost should NOT, never ever differ.