In this tutorial you will learn how to use Oblong Tessellation to get better results with long, skinny sculpts like pipes and chair frames. I use Oblong Tessellation for many other things too, so it’s a useful tool to add to your own knowledge.
The Long and Short of It
A lot of you probably looked at the term “Oblong Tessellation” and went cross-eyed. Don’t worry. I did too.
But after looking into it, I figured out that it’s just a freakishly complex name for a pretty simple concept. All we’re doing is rearranging the sculptie’s vertices so that instead of a perfect square 32×32 grid, we have a rectangular grid at 16×64, or 8×128.
Above, you can see the difference between a normal sculpt map and one that uses oblong tessellation.
Why is this useful? Let me break it down for you.
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 Now take a look at the cross section of this pipe and you’ll begin to see the problem.
There are 32 points on every edge loop, which is a problem in more than one way. First of all, you don’t need 32 vertices to make something that skinny look round. These are wasted vertices. Second, sculpties start doing weird things when you have a lot of vertices in a small area. The more points you have in a small area, the more chance you have for jagged edges when you import that sculpt into Second Life. |
So. What do we do? We make an oblong sculptie! This is pretty easy to do. When you bring up the dialogue to create a sculptie, by default it shows 8 x 8 faces with 2 levels of multires. Change this to 4 x 16. When you enter the number for Y, initially, it will turn black and the Build button will be greyed out. Usually this just means the dialog wants you to press Enter so it can recalculate your sculpt mesh.
Look at the cross section of this new sculptie.
Now each edgeloop has half the number of vertices, which is still plenty to make it look round. We aren’t wasting nearly as many points, and we won’t have so many problems with edges becoming choppy.
What’s more is, those points we took from the diameter of our edge loops now go into making the length of the pipe. We can add even more bends. (Or we can work with multires so our pipe doesn’t loose it’s shape at a distance.)
Look at the difference between our original pipe and the oblong pipe. We have a lot more to work with. This doesn’t just apply to pipes. It’ll work for anything that has a long, skinny shape, like the frame of a dining chair, or scaffolding for a building, or a streetlamp, or a pencil twisted in the shape of a heart!
Baking an Oblong Sculptie
Domino’s new primstar scripts automatically assigns your mesh an image sized based on the faces and and subdivision levels that you started with.
So if you started with a mesh with 8 x 8 faces and 2 subdivision levels, it will assign a 64 x 64 image.
If you start with a 4 x 16 mesh and 2 levels of subdivision, it will assign a 32 x 128 image.
In previous versions of my starter tutorials, I instructed people to start without subdivision levels (no multires) because I felt it was easier ( and I STILL feel it’s easier) to start defining a mesh with less vertices.
However, if you start with an 8×8 mesh and no subdivision, your mesh will be assigned a 16×16 image, which isn’t what you want. So now it’s better to start with the 2 levels of subdivision and then manually delete the higher levels if you wish to start with a simpler mesh.
Tips, Tricks, and Notes
Oblong Tesselation is still rather new and while I use it all the time now, I can’t, for the moment, think of any tips specifically related to it.
But as a note, there is some functionality of oblong tessellation that’s still being developed. Particularly the ability to use LESS vertices than the current 1024, which would be useful for certain simple geometric shapes.
