Jump to content

When you think it can't get any worse...


You are about to reply to a thread that has been inactive for 3350 days.

Please take a moment to consider if this thread is worth bumping.

Recommended Posts

I came across this. From the Wiki: http://wiki.secondlife.com/wiki/Mesh/Mesh_physics

NEW An additional factor has been added to this computation. 
If a linkset is made physical, it will incur an additional penalty
that will depend on its scale.

What this means can you see in the following pictures. When I have this boat on my parcel, and jump on it for a nice little boat trip, it can result in an auto return due to it's way higher prim count. :matte-motes-shocked: Well, I'm not amused at all about this, and I see not much fun left for meshes besides attachments. But who knows, maybe the mesh attachment killer is in the works, too?

 

Non physical 95 prims / physical 168 prims :matte-motes-zipped:

WTF01.jpgWTF02.jpg

Link to post
Share on other sites

@Medhue,

exactly what I thought!

@Jayvell,

yes, really!

@Constance,

the boat is a work in progress, so it's not fully optimised yet. The entire boat is currently 7606 triangles in Highest LODs. It has some furniture inside already. It's 2130 Tris in Lowest LODs. It's ~17 meters long, and the Tuna Tower on it's own is ~10.5 m x 5.2 m x 12.8 m. So a couple of it's parts won't get any benefit in PE from lowest LODs anyway.

Though, I could live even with 95 prims. But It make not much sense to me, that I develop the boat any further, with the new physics cost change. I made very simple physics meshes for it already. Most of it is just box physics shapes. The Tuna Tower is Physics Type "None" already (It has a box as phys shape, too). But there are a couple of pieces that needs proper walkable physics, like the Hull and the Cabin. But even those are very simple custom phys meshes. So I could achieve the 28 Physics Wheight.

Infact, I have to blow up it's triangle count to a non physical PE of 169 at the current state, to avoid any accidentally, random return on the parcel. :matte-motes-zipped:

 

 

Link to post
Share on other sites

Have you tried to set the physics type to none for all elements which do not seriously add to physics behaviour ? I could imagine that for a boat to work appropriately in SL its physics shape could be a simple brick ? That should bring physics cost down to near zero... Well, i must admit that i never played with vehicles, so i may be entirely wrong.

Link to post
Share on other sites

Bravo Arton, 7606 with some internal furniture is already a very economical model and a superb example of low polygon mesh modeling. It is absurd that it's PE is 95 prims without physics and 165 prims with physics is an absolutely insane prim count.

The point is that 1 sculpty = 2048 tri polygons, so your lovely boat model is equal to less than 4 sculpties - tri polycount wise

And yes, I'd say the railings are necessary. What if people were to fall off into the water and weren't wearing their Swimmer or a life jacket !!  Safety first !

I have to repeat this again. Arton's 165 prim boat mesh tri count is equal to less than the tri polygons of less than 4 sculpties and you shouldn't have to live with it being 95 prim.

For this boat to compare and compete with the sculpty equivelant on prims it's PE should be no more than 10 prims or 20 prims with physics maximum

What is the point of mesh with these high PE counts

Of course you could make a necklace out of your boat and wear 40 of them on a chain around your neck or prehaps wear it as a hat :matte-motes-wink-tongue: 

Link to post
Share on other sites

I wonder what the driving force was behind them adding mesh. If it was just to stop people whining about custom avatars then I can see why they are sticking it to us on vehicles and other non attachment meshes. If they make the PE weight so high it's not worth making it a mesh, then the whole "the  prim sky is falling" crowd will calm down, but the attachment people will still have their goodies.

I'm really starting to worry about how many things they are holding off till after release. I have a sick feeling they are going to leave us hanging on all those other features, filed away in the to be done box with all the other features we've been promised that never made it in.

Link to post
Share on other sites

LOL This rather poor looking TurboSquid version: Polygons: 19300

What's the point of your post?

@Gaia,

as I said already, anything that don't need any collision is "PrimType None" already.The rest is box physics shapes. And those parts that are not boxes are very simplyfied already. It makes not much sense to me to simplify it even further. The result will be a poor looking boat, with ridiculous collision, with a still ridiculous high prim count.

Link to post
Share on other sites

A little off the main topic but regarding the triangle counts for mesh vs. scuplty.... you can't make a direct comparison that a single mesh with 2048 triangles holds the same weight as a single sculpt with the same triangle count.

This is because sculpted prims are still programmatically created... at least more so than true meshes. All sculpted prims always have the same number of vertices, the same edges connected to the same vertices, and the same texture mapping across the sculpt. Also, the LOD reduction is always the same. Because all of these things are the same for every sculpty, it streamlines how the servers and clients can deal with sculpts. Like prims, they are still remarkably easy to stream across the internet to viewers.

But when we introduce meshes to the scene, everything that was once predictable now is up in the air. Each mesh has its own vertex count, its own unique edges, mapping, LOD, physics shape, etc. None of this can be assumed or easily guessed by the server/viewer. This therefore makes meshes a lot more expensive on all fronts. A mesh that has fewer triangles than a sculpt still causes much more stress on the servers comparatively.

Link to post
Share on other sites

Arton, can you please give me a copy of the boat? (And, if possible, the .dae that it was uploaded with--you can make a jira and include that privately, I believe). I'd like to see if it could use further optimization as well as see how its impact on the server compares to its cost.

 

The decision to add a penalty for dynamic objects based on scale came from testing which showed how easily a number of large, dynamic objects could bring a sim to its knees. However, the cost that we've associated with that penalty (4%/m^2) was deliberately chosen to be at least a little too high. That's because we need to see how meshes are used on Agni and what their impact is before we can settle on the exact values. Since we know we can't ever increase the costs for existing content, we wanted to start high and potentially lower it in the future.

Falcon

Link to post
Share on other sites

Just a weird idea ...:

 

  • double the number of Prims per region (15000 -> 30000)
  • double the PE per regular prim and Sculpty
  • Keep mesh as it is now

Then a sculpty would cost 2 PE and things get more comparable without breaking content. :matte-motes-evil-invert:

Link to post
Share on other sites

Falcon,

I have sent you a copy of the boat. It's an optimized version though. I caught a mesh that obviously had the HI LOD mesh for physics. Probably I messed up that part when I uploaded the boat after mesh deprecation. I optimized a few other parts as well. Simplified them untill I reached the lowest possible number of hulls, and have the collision still properly intact.

However, what I have now is:

Non physcal: PE: 84 / PW: 15.5

Physcal: PE: 91 / PW: 90.6

About the .dae files. Currently the boat is build out of 25 unique meshes, plus LOD Files, plus physics meshes.... :matte-motes-impatient:

Link to post
Share on other sites

Thanks Arton, I've received the boat and will check it out when I'm next in the office (Tuesday). Could you also send me the .dae file (via jira or direct e-mail)? It's worth pointing out, btw, that your total PE only went up by 7 prims as a result of making the boat physical. That does not seem bad to me.

I'm also looking into putting together a more detailed explanation of the reasoning behind the current physics weight calculations. I hope it will help everyone understand the tradeoffs involved and my motivations in developing the formulae. I truly believe that most reasonable builds should not be limited by their physics weight. In general, I expect the other PE factors to almost always exceed physics weight for well-optimized, legitimate objects (i.e., "useful objects" rather than pathological cases). 

Falcon

 

Link to post
Share on other sites

Falcon Linden wrote
: I truly believe that most reasonable builds should not be limited by their physics weight. In general, I expect the other PE factors to almost always exceed physics weight for well-optimized, legitimate objects (i.e., "useful objects" rather than pathological cases). 

 

That's because the other costs are unfairly weighted too high.  Your co-worker Runitai has stated that they are designing for graphics chips *below* the stated SL system requirements. Also the 250K triangle budget is based on a region full of mesh objects. A PC on the low setting has a draw distance of 64m, and can only actually see 20% of a region at a time.  The combined effect of these penalties ensures that parcel costs of mesh range from high to absurd relative to sculpts.

Another way to put what you stated above is "don't worry about physics cost, because we made the other costs so high". That may sound a bit nasty, but that is how it looks from my perspective.

Link to post
Share on other sites

Honestly when mesh first came out I was excited. But here we are almost into august, the earliest mesh could have been fully rolled out full grid, is coming up, and here we are. Staggering penalties, ridiculous PE's etc etc.

Gotta say all this makes me wonder if I should just stick with sculpts and douse any hopes and dreams of viable mesh in SL. With the penalties  for everything from scaling to physics it nearly defeats the purpose of mesh in the first place. By the time lindens are finished, there won't be anything you can't make with mesh that you couldn't just do for cheaper or just as well with sculpts.

honestly dissapointed.

Link to post
Share on other sites
You are about to reply to a thread that has been inactive for 3350 days.

Please take a moment to consider if this thread is worth bumping.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...