Tuesday, January 31, 2012

The Truth About Mesh

A customer wrote me the other day, saying how much she loves my things -- but is everything I make from now on going to be mesh?  After all, since Phoenix became mesh-enabled I have had a new mesh release every week.  She was wondering because she "still is not understanding this mesh" -- and she is not the only one.

Before I tell the answer I gave her, let me explain as clearly as I can about mesh rezzed objects -- not worn mesh like clothing and avatars, which I know little about.

First, understand that everything in SL is actually made of mesh, whether regular prims or sculpts -- and mesh is just a bunch of triangles.  If you change your viewer to Wireframe mode, you can see that this is true, as in the pics below, one in regular view and one in wireframe. Yes, even a regular prim cube  IS REALLY A MESH (made of 24 triangles)!

This August "mesh" was introduced -- by that is meant, generic mesh, the kind that is used in all games, and not some special limited type, like prims or sculpts. Without getting all technical, using this mesh means nearly infinite flexibility, without the limitations of sculpts, and also means you can often do more with fewer prims.  

Some facts about mesh objects rezzed (and not worn):

1) You can modify mesh as you would any sculpt -- scale, tint, texture.

2) Unlike sculpts, and like prims, mesh can be created to have up to 8 different faces that can be textured and tinted differently from one another.  For example, these two doors and two drawer pulls below are all one mesh object, but have different textures applied -- I could also tint the doors or pulls separately from each other, even though they are one mesh object. 

3) Mesh doesn't use a sculpt map; it is not made from regular prims; it cannot be created inworld.  It is made in a 3D program and imported into SL.

                                 THE BEST PART: MESH AND PRIM COUNT / LAND IMPACT

A customer (one who had been happily buying mesh products) had build her own house, entirely of regular prim cubes.  I told her to go into her (mesh) viewer's Edit > Features Tab and change the Physics type to Convex Hull instead of Prim. Instantly the prim count went from 173 to 87.

How?  Because now there are now TWO PRIM ACCOUNTING SYSTEMS IN SECOND LIFE, and you can choose which one you want to use for each object. The new term for Prim Count is Land Impact (LI), which means "how many prims are actually deducted from your total available in About Land".  It is almost certain that many of your objects can be reduced in LI like this -- but many others can not or can even double in prims -- you have to know how to tell the difference, which is not as complicated as you might think, because:

Jenni Darkwatch has written a complete, SIMPLE explanation HERE.

Try it yourself with a mesh viewer:  Rez two cubes and link them. Check the prim count -- it will say 2 (2) (the second number is the Land Impact or actual prims counted against your parcel total).  Now go into the Features tab and change the Physics type to Convex Hull -- voila, one prim!

Bottom line:  Anything made entirely of regular prims (except torii/donuts) and unscripted, try making Convex Hull.  Huge objects, however, can have a much higher prim count.

Consider this:  Every sculpt mesh must have exactly 2048 triangles, whether you are making a mountain or an olive. 2048 is way too many triangles for some things, too few for others. It's like baking a cake when you must use exactly one cup of sugar in everything -- too much for some things, too little for others. For the new mesh, you can use only as many triangles as you need, keeping the prim count/Land Impact as low as possible.

For example, the two doors, drawers, and pulls in the mesh pictured above has a prim count of one.  No way could I have made those with a prim count of one with anything but mesh.


An informative blog post explaining mesh is HERE.

So, the short answer to my customer's original question is that most of what I make from now on will be made of mesh or a combination of mesh and regular prims. For 3D artists, the ability to make much more detailed 3D objects is just too irresistible. It's like, once you discover Legos, you are not going back to Tinkertoys.  

For a fuller explanation of why I am a mesh supporter and some explanatory pics, read my blog post HERE.

Friday, January 20, 2012

Why I changed my mind about mesh...

I was very skeptical that mesh would improve Second Life -- and I still have the same reservations, mainly about the relative ease of importing ripped models, compared to say, sculpts, which only exist in SL. I also did not want to have to learn Blender -- well, I wanted to, but had serious doubts about my ability to do so at more than a basic level.

It's just that now, for me, the pros are outweighing the cons.

The first of these is the ability for everyone to cut prim count (now called Land Impact or LI) by 40% not only with mesh items but with  unscripted items which are made entirely of regular prims (except torii/donuts) -- and sometimes even with sculpts and/or scripts.  How?  Using a mesh enabled viewer, select the item, go into the Features tab, and change the physics type to Convex Hull.  Try it first with two plain cubes - two linked cubes set to convex hull = 1 Land Impact (or Prim Count).

Second is that for the first time, I can actually choose almost any furniture design and not only make it with a reasonable prim count -- I mean Land Impact! -- but do a far better job of making it look exactly like I want. Artistically, mesh is simply irresistible!  I never want to go back to trying to make sculpts and prims look like real furniture. Making mesh things is just too much fun (well, when not beating my head against the Blender wall), and my things just look way too good!

Mesh has done for SL content what Windlight did for the environment -- and yes, unfortunately, some computers may not be able to handle it.  And that is NOT because mesh is harder on viewers than prims or sculpts, because they are definitely not -- it's the viewers themselves that just seem to require more processing power, no matter what they are rendering.  Hopefully later versions will be faster.

I don't know if this honeymoon will last -- how long before the grid is flooded with thousands of ripped models? But for now, I am glad that SL just got a big boost in quality. Here are some pics of some of my mesh sets: