Category: 2011 Project Updates

Mesh is coming: testing on the Main grid has started, LL are feeding us snippets of information and those watching it draw nearer are getting excited / concerned / upset / indifferent.

But what exactly does it all mean for those of us who have only a passing interest in such things? What will be the impact on the consumers among us rather than the content creators? What are we going to be seeing, what do we need to be aware of?

There are a lot of very basic questions such as these that are being asked – some of which are, in fairness, addressed in the SL mesh wiki pages (albeit with a lot of techspeak) – so I thought I’d try to put together a very simple outline of some of the key aspects to it all.

Note that this is not in any way a technical discourse on mesh and its pros and cons or how to create and upload mesh objects – articles penned by others far more competent than I are available in a number of blogs. Nor is it meant to be an exhaustive overview of mesh. It is simply a primer on the subject from the point-of-view of the consumer rather than the creator, and a look at what some of the fuss (good and bad) is about.

What is mesh?

A mesh – or rather a polygon mesh – is a means of generating 3D computer graphics. Polygon meshes come in a variety of forms, and can be created using a range of software applications. Second Life actually already uses meshes to some degree: avatars, for example are basic mesh objects. “Mesh” within Second life therefore really refers to the ability for users to create polygon mesh objects using suitable 3D rendering tools and then import them into Second Life for general use.

Why have mesh?

Second Life has often been critiqued for it’s somewhat primitive look: the in-world tools and shapes can be very limiting when it comes to trying to replicate more organic, natural, and real-world shapes. The use of mesh should allow content creators and Second Life users to import far more realistic-looking objects and items, overcoming this perceived limitation.

Three types of mesh can be imported into Second Life:

• A simple mesh is a mesh with a single face. It can have a single colour and texture
• A multi-face mesh is a mesh that can have multiple colours and textures
• A rigged mesh is a mesh that conforms to your joints and motions. This means that you can wear a rigged model that changes the length and orientation of your avatar’s limbs and animates accordingly.

Note: it is possible for a mesh object to be a combination of these types; it can, for example be a multi-face rigged mesh, like “Seymour” in the image above. Meshes can also be textured prior to upload, as a part of the creation process, or once in-world.

Mesh objects for use in SL can be created in any 3D modelling tool that support the use of Collada 1.4 .DAE files for export. Such tools include high-end applications such as Autodesk Maya ($3,000+) through to the free tools like Blender and Google’s Sketchup. Linden Lab maintain a list of suitable applications on their wiki pages.

Common terms associated with mesh

Those familiar with building in SL may find it easier to consider mesh in the following ways:

• Mesh – A collection of triangles with a single transformation matrix, roughly analogous to a “Prim” in SL (although not necessarily the equivalent of a prim – see PE, below).
• Submesh – A subset of a mesh, equivalent to a face/side on a normal prim.
• Model – A mesh or collection of meshes, equivalent to a coalesced (or linked) prim object.

PE – Prim Equivalence (now Land Impact)

Prim Equivalence (or to give it the official title: Prim Equivalent Weight) – abbreviated to PE, is one of the most important concepts for the “casual” mesh user / consumer, as well as a vital consideration for mesh creators. It has also been the subject of much controversy even before mesh has been launched on the Main grid. So with these points in mind, excuse me if I go on about it at some length.

Basically, PE is a means of trying to ensure that mesh objects and traditional prim objects receive fair shares of Viewer and server resources. Perhaps the easiest way to understand PE is to think of it as the number of prims that would be required to achieve the same level of detail, were they to be used instead of the mesh object.

PE itself is arrived at by taking the highest result from three performance weighting calculations made at the time a mesh is uploaded to Second Life. These are:

• The server weight – (also referred to as the simulation weight in the wiki) the impact an object has on the server-side resources needed to manage it.
• The streaming weight – essentially the bandwidth required for an object to be downloaded to your Viewer and rendered. Basically, the more complex the object = the higher the streaming weight
• The physics weight – possibly the hardest to grasp, refer to the complexity of an object’s physics model. (This is also where Viewer developers have issues with coding their Viewers to enable mesh uploads, as I’ve reported on previously, as the code used by LL to calculate the physics weight utilises the Havok physics engine, which is not open-source. Therefore TPV developers need to find a means of calculating the physics weight either by using a suitable open-source physics engine, or by obtaining a Havok license.)

These weightings are calculated based on the complexity of the mesh itself and how well it has been defined and optimised during the creation process; they can also (in the case of the streaming and physics weights) be adjusted during the upload process. Get everything right, and a mesh object should have a manageable PE value. Get anything wrong, and one can end up with a horribly-massive PE count.

And even when it is done right, it is possible for an object to still end up with a PE count in the high hundreds, or for a mesh object to come off less favourably than it’s prim / sculptie equivalent (take a mesh tree with a PE of 9 or 10; are you more likely to buy that, or a sculptie tree that is just 1 or 2 prims, even if it is of a potentially lower visual quality?).

The PE for a mesh object can be seen using the Build menu of any mesh-capable Viewer, as shown below.

Continue reading “A very *simple* guide to mesh in SL” →

Linden Lab have issued a further mesh update, detailing the Mesh Upload status page is now available on Main grid user dashboards.

As I reported a week ago, the new status page can be located by logging-in to your dashboard at www.secondlife.com. When your dashboard is displayed, click on ACCOUNT in the menu at the top left and then Mesh Upload Status.

For an overview on getting yourself certified to upload mesh, see my earlier post on the subject.

Tateru Nino relays the news that Mesh imports to Second Life are to be separately gated. According to the SL wiki page on Mesh Upload Enablement:

“In order to prevent usage of intellectual property with the mesh upload tool, prior to uploading a mesh with a Mesh enabled viewer, 2 checks will occur before the user will be allowed to upload. The first check will be to verify payment information is on file and the second is a chance to educate the user with a short tutorial. After the user completes the tutorial, they will be enabled to upload content.

“A flag will be added to the CSR tool which will allow supoort [sic] to enable and if approriate disable the ability to upload mesh. The viewer will use the user’s enable mesh flag to activate the upload mesh capability. If it is disabled, a message will appear and a link to the secondlife.com link for the tutorial. The scope of this testing is to confirm expected results for this setting on Mesh and non Mesh viewers as well as test the tutorial and ensure it enables mesh ability accordingly.”

Once the criteria of having PIOF and going through the tutorial have been met, people will essentially be “licensed” to upload mesh creations. However, like any license, the ability to upload mesh can be revoked:

“If Lab determines user is in violation of IP mesh upload terms, user can be indefinitely flagged as not mesh enabled regardless of how many times they continue to complete the tutorial.”

Clearly this is intended to help deal with matters relating to IP and copyright violations, DMCA claims and suchlike, all vital to protect the authors of mesh files and content in the event of theft. Let’s face it, the whole issue of IP and copyrights are convoluted when it comes to mesh; therefore caution is required.

 Take a look at the picture on the left. It’s a mesh model of Frank Lloyd Wright’s famous Kaufman house, “Fallingwater”. It’s available on a website for $75.00USD. It can apparently be purchased legally.

But who actually owns the copyright? The website? The creator? Or the Frank Lloyd Wright Foundation?

The question is important because the FLW Foundation is jealously guarding anything and everything it considers to be its intellectual property. Just last year, after cooperating with it, they issued cease and desist letters against the Frank Lloyd Wright Museum in Second Life, forcing it to close its doors. As such, who is to say that even a product like this, brought in good faith, will not land someone wishing to upload it to SL up in a world of hurt? And the FLW Foundation isn’t alone in guarding its property.

Right now, mesh is the elephant in the room; hard to ignore, but not the easiest thing to deal with. The risk of copyright violations, claims of illegal usage, the potential involvement of legal teams from major organisations is a risk; just a glance at all the Star Wars, Star TreK, DC Comics and other meshes available off the web has to give rise to the question, “Yes, but how much of it is actually licensed? Ergo, Linden Lab need to take steps to protect themselves against major upsets and openly discouraging people from knowingly uploading content they shouldn’t be bringing in-world – and making the accounts they use to upload said content personally linked to those using them is certainly one way of going about it.

But it also means that those creators who would stick to only uploading their own creations but who have preferred not to / been unable to give PIOF are going to find themselves ostracised, and this could well result in the new requirement being subject to upset and consternation.

Gating uploads also has a secondary potential benefit: mesh is both an unknown quantity and a complex subject. While it has been under extensive testing on the beta grid, its still not entirely clear as to what impact it might have on the main grid – and there is a risk that poorly-developed meshes could do more harm than good when it comes to sim performance. Ergo, providing a means of blocking ill-developed models from being imported until such time as the creator can improve their technique and keep within whatever parameters are required without having to block their account in its entirety would also seem to be a wise step to take.

The Mesh timeline has been published. Well, “timeline” is a bit of a stretch, but the details are now out. To save you from clicking a link, here’s the announcement in full:

“Of all of the things that excite us about Second Life, and there are many, Mesh is near the top of our list. Since the Mesh Project Viewer has been available, many content creators have given it a try on the test grid and we have only seen a small glimpse of the unlimited creative potential that this technology brings to Second Life. On behalf of everyone at the Lab, we want to thank everyone who have participated in the test and created these cool videos demonstrating the power of Mesh. 

“So, now that you are excited about trying it out on the Main Grid, we wanted to share the launch time line, as promised.

“In July, we will enable a limited set of regions to use Mesh and will it roll out, in a phased approach, throughout August. By the end of August, everyone in Second Life will be able to import Mesh objects. Of course, if we run into unforeseen issues or bugs, then this time line will need to shift. 

“We know that you must have a lot of questions regarding policies, costs, and how Mesh objects will be weighted. Although we cannot share these details yet, we will continue to keep you informed on our progress and other relevant news on this blog. 

“So buckle up and get ready for a whole new wave of creativity in SL.”

Or you can read the above here.

Mesh has been a long time coming – and the announcement is somewhat welcome, a little more depth-of-detail would have been helpful. I’m assuming at this stage that the regions for the initial roll-out will be connected to a specific Server Release Channel. If so, will sim owners on that channel be given the opportunity to opt out until later in the roll-out? Mesh is obviously a complicated subject, hence the caveats in this announcement – but I certainly hope we’ll be seening a greater depth of information as July draws closer.

It has been confirmed that Linden Lab will be publishing a timeline for the roll-out of Mesh at the end of May.

Note this is not the actual roll-out of Mesh itself; it is the timeline on what will happen when. It’s a good move on LL’s part: people have been hungering for Mesh for a long time, and all that has been happening on the Beta grid had increased overall levels of excitement / curiosity / confusion / demands to see it “now”.

Mesh is potentially one of the most revolutionary new aspects to be introduced to SL in a long time – at least in terms of content creation and technology. It will possibly completely redefine entire market sectors in terms of both the look of objects, how they are created and the skill sets required to produce them. It can be applied to almost anything – objects, building shells, vehicles, so the impact is potentially huge, although there do appear to be some limitations as to precisely what can be achieved  – and how much will be modifiable – within mesh objects.

Take just one market sector, the one I’m most familiar with: buildings.

The potential here is mind-boggling: beautifully sculpted exteriors to buildings that mimic their real-life (or fantasy!) counterparts, and for the equivalence of a few dozen prims, and fitted-out inside with traditional prim-made floors, etc.

Avatars are another area where mesh could revolutionise things. While our current avatars are themselves mesh creations, they are somewhat limited; augmentation currently requires the use of prims and sculpties – both of which can be cumbersome. Mesh imports allow avatars to be massively altered / augmented – so the potential here is massive, although there are allegedly some initially limitations as to what can be done with such rigged meshes.

Given the sheer scope of impact mesh represents, then defining a timeline / roadmap leading to its roll-out is undoubtedly a good move. While there is much about Mesh that probably won’t become apparent until after it is “live” – precisely how popular mesh designs will be, what they will do to the market sectors where they are principally used, precisely what the initial limitations will be, how these will be overcome, and so on, there is still a need for people to have as much information in advance as it is possible to give. This can only be achieved through full and proper communication and avoiding the desire to give into pressure to simply “get it done”.

We’ve waited a long time for mesh – kudos goes to LL for dealing with its arrival sensibly and in a step-by-by manner that has fully engaged with the user community on the Beta grid, and which look set to continue now on the main grid. Hopefully, the new timeline will do much to clarify where everything stands with regards to mesh, and in the coming months, we’ll see even more engagement between users and Lab as we move towards it’s arrival.

Further Information

• SL Wiki Mesh page
• Wiki mesh FAQ
• SL mesh Flickr stream