Doc:Tutorials/Modelling/BSoD/Curvyness
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[edit] Curvaceousnocity!
This tutorial will explore a somewhat overlooked area of the Blender toolset, that of curves.
So far we've looked at meshes that are created out of vert-vert faces, although we did see that we could "fake" new geometry by using the subsurf tool. Curves are another way of letting us model a complex mesh without having to worry about individual verts.
The first thing we'll be using curves for is to trace a few logos, so we'll start off by setting the background in Blender. Download this image to your computer and open up your head file from the previous tutorial.
Next we need to set the pretty image as the background, to do this, select the Background View option from the View button to the lower right of the 3D Window. Next select Use Background Image, then select the small folder icon and navigate to the image. Select the image with the LMB 
and press ENTER. Once you can see the image, close the little background selection window and we shall begin. But... We don't want to be editing over the face thing we've just made, so let's utilise another of Blender's fantastic tools, layers. To go to a layer, simply press a number button (along the top of the keyboard, NOT the numpad). Go to L2. I shall henceforth refer to layers as LX, with X being the layer ID.
[edit] Eye Of Horus
So, we could use a regular mesh to model the Eye Of Horus but it would require a lot of effort (and verts) to do so. Instead we're going to use Bezier Curves to "trace" the image. Make sure you're in FRONT view and center your screen on the background image, zoom so the background fills as much of the screen as possible. Now, add a Bezier Curve from the menu accessed with SPACE.
Again, Blender starts in EDIT mode, translate the selection so that the left hand vert (I'll call it a vert, although this is not really true) so that it lies on the top left hand corner of the eyebrow. Before we start editing, just a word on how Beziers work.
A Bezier consists of a vert and two handles. Normally the handles lie in the same direction as one another, but this can be changed. A segment is analogous to an edge and exists between two Bezier verts. The angle of the handles determines the shape of the segment. The images above show how the handle position affects the segment.
[edit] Editing The Curve
Ok, so let's get editing! Deselect everything and grab the right hand vert, make sure you get the vert, not one of the handles and translate it so that it lies in the middle of the eyebrow like so. Now, deselect all and seperately translate the two handles that affect our curve so that it follows the line of the eyebrow. The background in my image will look more faded as I've done this to make the screenshots easier to see. Also note how I don't really care if my curve doesn't follow the background exactly, as long as I get the rough shape.
Select the right hand vert and extrude to the right, place the new vert on the top right hand corner of the eyebrow. Now edit the handles so that the new segment follows the background image. It is tricky to get the hang of as you must remember that translating the handle of the middle part can also affect the segment on the left. Fiddle around a bit until you have it roughly correct.
Now extrude the right hand vert downwards so it lies on the bottom right corner of the eyebrow. There is no way you can use the handles to make the new segment follow the outline, so we're going to have to find a new way of manipulating the curve. Select the handles of the top right vert and the bottom right vert that affect the new curve and press V, this means the handle no longer has to remain in the same direction as its partner. Now you should be able to get the segment to follow the ouline properly.
[edit] Continuing The Eye
Continue extruding and manipulating the curve so that it extends to the bottom left corner of the eyebrow. to join the last two verts together press C (Think completing a circle). Select the appropriate handles (the ones that affect the new segment) and press V to get the correct edge.
Now, add a new Bezier Curve whilst you're still in EDIT mode and move it to the top left corner of the main eye. Follow the outline of the background and refer to the following image until you have traced the entire eye. To do the inner part, you'll need to add a new Bezier Curve again. I'm not walking you through this as it uses nothing not mentioned before. The only thing to remember is that V allows you to manipulate one handle without affecting two segments.
Finally, press Alt C and confirm the dialog that pops up. This converts the curve into a regular mesh, we can now extrude in SIDE view so that it has some depth. Click here to go to the Part II.
