05_second life

The plan
My main plan this term is to contact all the people i may need to help me with this project.
This will include: artists working in similar areas, 3d gallery owners, the rapid prototyping industry, university engineers, 3d print technicians, art/science funding bodies, that student in tokyo who apparently is doing the exact same project!…etc.
so i need a mini portfolio which is as clear as possible and to do this need to make some demos of what i intend to do with 3d sculpture. i decided the best way to do this is as a 3d virtual exhibition, backed up with still imagery naturally. so i’ve been looking at ways to achieve this. first the hottest virtual world around:

slgallery.jpg

second life – dispiriting
lost souls wandering around deserted landscapes interspersed with obscene amounts of advertising for stuff you don’t want. so a pretty good model of the real world. the word dispiriting is appropriate – could be read literally – lacking spirit – just like the hundreds (not millions) of mostly silent shells = avatars plodding around. the whole exercise feels a little blank, however there are occasional highspots – or just above lowspots, mainly in the field of 3d art + architecture. something like 60% of users of second life actually contribute something (ie build 3d objects to litter the place – this being second life’s ostensible prime purpose). this is a huge figure relative to other internet collaborative genres – for example something like blogging is at the 1% level. that is for every 100 people reading blogs, 1 person writes blogs. (by the way this figure is amply illustrated by wikipedia & the madigitalarts wikispace in particular – which i seem to have written about 99% of). so 60% of people creating stuff sounds like a good place for a 3d artist to be. however there is a problem, well there are several problems, but the main one is that the tools they give you to create original stuff with are total crap. (total crap unless you want to build yet more empty office blocks)

here’s a question:

what do these two images have in common?

sl1.jpg

the answer is they are the same thing! welcome to the weird and brutal world of sculpt maps, second life’s very own 3d format. first lets look at some normal 3d formats, including ones i’ve used already on this project.

3d file formats

Most 3d file formats seem to build up models from a series of hundreds/thousands of polygons. often triangles. the file is stored as a hierarchical sequence of geometric vertice points like so:

A typical OBJ file in part looks like this:

# this is a comment
# Here is the first vertex, with (x,y,z) coordinates.
v 0.123 0.234 0.345
...
...

Part of an STL file might look like this

solid cube_corner
facet normal 0.0 -1.0 0.0
outer loop
vertex 0.0 0.0 0.0
vertex 1.0 0.0 0.0
vertex 0.0 0.0 1.0
endloop
endfacet

Part of a VRML file might look like this:

coordIndex [
33518,34639,35491, -1, # triangle 0
33518,35491,35034, -1,
33518,35034,33888, -1,
33518,33888,32987, -1,

So what is happening with the Sculpt Map file which looks like this:

sljuicer.jpg

guess what that image makes? (answer at end of post)

Sculpt Maps 

Each color pixel on a sculpt map is an RGB value. These three values can be mapped to the XYZ coordinates.
So that part is understandable, but why is the map always a square shape? Well this is the only allowable shape = 64*64 pixels = 4096 points. Which is a very small number – the small ring of men

man5ring.jpg

i exported from Poser 6 into Rhino last term had 4.4 million vertices, so you can see there’s going to be some big problems here. Secondly how is the square sculpt map mapped to a 3d object. well if you think about the fact that a donut is mappable to a square (and often is for computer games especially cellular automata) on a one to one basis you start to see how the Sculpt map might work – each RGB pixel is next to its neighbours on the finished model and the edge pieces wrap around. i’m not clear on the details here – and find it fascinating, but can see that it is way short of what i need to get my models into second life. I’d have to split them up into many parts (preferably convex ones as far as i can tell) and then make sculpt maps for each one. there’s a demo of a quick and crude way (the best there is at present) of doing this here:

http://home.comcast.net/~pixelforgeltd/Tutorial.htm

it involves using 3d studio max which i didn’t have much joy with before, but i’m waiting for the college version to become available – i may have another look.
The technique involves creating a circle mapped to the 64*64 grid and then wrapping the circle around the 3d object you wish to sculpt and then sucking the air away as best you can. It’s pretty tricky as can be seen by the ear of the head above. The best i’ve seen is here

slman.jpg

from a sculpture gardern in OYSTER BAY which is made up of about 20 sculpt maps stuck together. you can see some crude modelling on the hands in the lower image. Also it helps if your models are mainly convex – so this would be another problem.

The Sculpt map just encodes the shape of the model – to add color/texture you need a second map – this also is squished onto a square 64*64. here’s an example:

tut11.jpg

So for now i’ve decided that second Life is not right for this virtual portfolio – which is a shame because it is certainly easy to hype second life projects currently) and i do enjoy messing around in there. I expect and hope that someone will build some open source software to convert automatically from 3d models to sculpt maps soon, or better still Second Life update their allowable formats.

By the way to upload each Sculpt Map cost 10 Linden Dollars. And you get none to start with, you have to earn them. Well how do you do this – by various dull and painful techniques such as filling out web surveys for more stuff you don’t want to buy. Or you can work for someone else in Second Life – i met a Palace Slave avatar scrubbing a floor the other day, she said she would make L$40 in about two and a half hours!

Geometric Prims

But you can create geometric primitives (prims)  for free – these are triangles, squares, cubes and so on. No wonder there are so many tower blocks in second life – organic shapes cost money. So the idea would be to create 4000 or so triangles and then orchestrate them to fly into the right formation to make your 3d model. This would have to be done algorithmically and i may look into this, just as long as i don’t have to press create triangle prim 4000 times.

Here’s an example of a figure made in this way by Henry Segerman:

sltetraman.jpg

I see i’ve spent a lot of time discussing Second Life, considering i’m not likely to use it in the near future. I guess it has that kind of draw for 3d artists – but it has a long way to go.

next i’ll look at some more useable virtual gallery techniques.

—-
The answer was:

sljuicer2.jpg

a juicer!

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One Response to “05_second life”

  1. Henry Segerman Says:

    “By the way to upload each Sculpt Map cost 10 Linden Dollars. And you get none to start with, you have to earn them.”

    …or you can buy them, at a rate of around L$ 270 for each US$. Many people also use the beta test grid to upload test images for free.

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