From TechSlop
Sculpties have come to Second Life. The main grid, that is. After a few stints on the beta grid, a few funky rotations and flippings have been taken care of. Don't you just love ferreting out the funky things, working around them, and then they get fixed? It's a love/hate thing.
A sculptie is basically a sphere that gets molded. There are like 32 verts from pole to pole and 32 verts around the equator. Or maybe it's 31 verts here and there. Or maybe it's 16 verts from pole to pole. I'm not really sure because these things confuse me. Dividing by two, multiplying by 2, and offsets of +/- 1 really confuse me. Ain't it grand being a genius?
It's a sphere that gets molded. The mapping is spherical which means that the mapping looks like a mercator map.
So, how do you mold this sphere known as a sculptie? With a texture - a very special texture. This texture kind of encodes XYZ positions into the RGB values of the texture. This means that we are dealing with RGB space and it looks something like this:
The red channel is X position, the green channel is Y position, and the blue channel is Z position. So, just the R/X channel looks something like this:
Now that is spiffy.
So, let's make an egg in 3DS Max and get into Second Life as a sculptie.
So, I actually did up a decent workspace for 3DS Max. I started in Photoshop and made a 2d egg shape to act as a profile. With this profile on 2 different axis in Max, should be no problem.
Now, one thing I've learned over the years is getting colours to work together in a visual manner. When making profiles like this, I never use pure white because wireframes in Max get lost. And there are several other colour considerations, but I'll leave them up to you to discover. I'm so nice like that.
The modeling method I'm going to use is the one that Gearsawe Stonecutter shows in his tutorial. But all I'm going to borrow from Gearsawe is the cylinder. I will be using my own shader for baking the sculptie map. This will cause a scaling problem as we'll see later.
And here we have it:
The cylinder is 32x32. Once laid and placed, I converted it to an Editable Poly and deleted the top and bottom caps. Since I used Generate Mapping Coordinates when I created the cylinder, the UVW mapping is proper, which is yet another subject I will have to cover later.
Time to get busy shaping that thing. In Line mode, I selected a line, Looped it, and scaled it in X and Y. Remember that there is a difference between Loop and Ring. OMG there is a difference.
Tedious? You bet.
Eventually I get most of it. It's still a bit lumpy, but I'm not in the mood for uber precision. If I had bothered aligning everything instead of using my eyeballs, it would have been much better. But at a distance, not too shabby.
Just for fun, I tossed on my shader and took for a quick test render.
Yeah, it looks fine to me. Lumps? What lumps?
With the shader on the egg, time to bake it.
When it comes to what dimensions to use, there is still some unknown territory. I'm not too worried about it because this is an egg and Shack Dougall is doing some damn fine work in this area.
Decided on 64x64 and this is what I get:
At a glance, I don't see anything obviously wrong with it. Time to upload and test.
Here we go:
What is that? Seriously, what is that? Is that a fat egg?
Yes, it is a fat egg. Why is it fat? Because the shader uses local space - the bounding box. And said bounding box is not a cube.
After some quick scaling with my eyeballs, something a bit more eggish kind of appears:
So eventually we end up dealing with ratios, scaling, and resolution. This is something I will talk about when I get to talking about the shader.
