Cell Shading Explained

While I think this thread was great, I think it'd be more beneficial to have an actual tutorial in the forum instead of an in-game clickie. No offense!

So here's my cell shading tutorial. I'll post screenshots when I get home from worka.

1) Create two objects. Typically I prefer spherical but I guess you can use whatever you want. Whatever shape you choose though, the two have to be identical to each other. I don't think trying to cell shade a cube with a pyramid would look too well.... So for the purposes of this I will assume it's two spheres.

2) Make one object larger than the other. I typically choose a difference of 0.70, but I prefer a little thicker shading. I also prefer to enter the numbers manually into the box instead of dragging the little green/red/blue things around and hoping. If you don't know how to do this already then maybe cell shading is something you should wait to learn.

3) Texture, color, etc the smaller sphere. The smaller sphere is going to have the main color or texture.

4) For this step you HAVE to have an alpha texture. If you don't IM me in-game and I'll send you one. An alpha texture is a transparent one. Texture or color the sphere whatever you want the edge to look like, typically black.

4a) Now make it completely hollow - all the way up to 95. Cut away enough of the sphere so that you can see the inside of it, half is good enough. Go back to the edit dialog and choose select texture and make sure you select the OUTSIDE plane of the sphere. To this plane you apply the alpha. Seal the sphere back up again, ie, get rid of the cut.

5) Now all you have to do is move the two objects on top of each other. If you did it correctly you'll see through the alpha texture and into the inside edge of the top sphere, and the outside of the smaller sphere. A hint for this- SL currently positions objects based on their center. Those XYZ coordinates are really the center of the sphere, not the outside or corner etc. So if you copy the same coordinates between the two the two spheres will occupy the same center, and tada!

6) Link the two together and you're done. The only drawback to cell shading is that you have to tear everything apart if you want to change a color or texture, so keeping the objects you use simple is best unless you know you won't change anything.


I hope this makes sense, if anyone's stuck feel free to IM me, or IM me if I sound crazy.

For spheres you don't need a transparent texture for the object. Also you only need a single sphere.

1. Create a sphere

2.Texture it blank, color it whatever color you want it to be

3.Make the sphere 90 percent hollow, 180 B and 180 E twist

4.Select the outer surface texture, color it however you want it shaded

5.Done. Enjoy!

well nyaah. ;D but I wanna waste two prims for the sake of oneeeee. hehe.

Oddly, this single-prim method produces a sphere that reflects light in the opposite direction from the two-prim way. What exactly is happening when you twist a sphere, anyway? Is it just my vidcard, or is the thing warping in a very strange, non-physical way?

Great tutorial Joshua. Thanks for sharing.

Way to point people to my noobitity! lol

Great thread Josh ... If only it had been there when I had an attack of ignorance. Keep it up.

Anyone think this may work for a lightsaber-type effect? I've been using two cylinder prims to do this, one inside the other, the inner one being blank white, the outer being transparent green. It's not quite right as the transparent green gives a green tinge to the white core, as one might expect.

My aim is to get the white "core" showing through the green "glow" clearly. Any ideas will be appriciated.

Very well written tutorial, Josh, but there's no need to tear things apart just to change textures. All you need is some mastery of camera control. Make sure either "Select Texture" or "Select Individual" is on, and then move the camera into place so that you can select the surface(s) you want to affect. Proper camera control takes a little practice to master if you're not used to 3D modeling, but it's arguably the most crucial part of being the best modeler you can be, and it saves you oodles of time.

For all bojects except spheres, this is really easy. Let's say you want to change the inside prim of a cell shaded cube from red to blue. Just hold down alt, click and hold on a surface of the outside cube (wherever you've alt-clicked will become the camera's pivot point), and then move the mouse so that the camera swings through the outer prim. Once the camera is in place, let go of alt, and click on the inner prim to slelect it. Now just change the color, the texture, or whatever. Done.

For spheres it can be a little trickier, since using a sphere as a pivot point will often cause the camera to simply orbit around the sphere instead of going through it. To solve the problem, simply alt-click on any nearby flat surface (you can use the ground if it's close by, an existing prim, or if nothing flat is already vailable, just temporarily rez a cube right on top of your sphere), and then you'll be able to swing the camera right through. Select the inner prim, and make your changes.

With a little practice at controlling the camera, you can easily select objects that are inside other objects without having to take them apart. Have fun.

It probably would work fine, try varying the hollow % tho