A little while ago, somebody asked how to sculpt a sword. Since this is also a good example of how to leverage some powerful features (subsurf in particular) to let Blender do the work for you, I thought I'd write down my take on it. This is geared towards making sculpts in Second Life, and as such requires the Primstar (or Jass) plugin to set up the sculpt object, but the rest of the workflow is not unique to sculpts.

This is written as a "stream of consciousness", to show my workflow, rather than as a manual for the Blender functions, but the ideas should be easy to play with and suss out how to apply to other situations.

-I may do something clever with the images later. For now, just click them to get a full-size view.

Sculpting a blade

Start (obviously) by adding a sculpt mesh. (Add/Mesh/Sculpt Mesh).

Unless you have a really good reason otherwise, “Cylinder” is almost always the safe bet. In this case, we’re going to make smooth, sweeping lines, so subsurf is a good choice, giving a few control points and letting the computer do the tedious work of distributing the faces nicely.

8x8 gives an even distribution, which, depending on what you want may be simple to work with, or lack some detail along one dimension. 8x8 or 4x16 are my standard choices. Let’s go with an 8x8 subsurf’ed cylinder.

Unsurprisingly, we now have a cylinder. Hit Tab to go into edit mode, as seen from above:

Hit a to select all, s to scale, and y to scale along the Y axis. (Check the small coordinate system axes in the lower left corner if you’re in doubt which axis is pointing where in your current view).

Flatten things to get a slightly more sword-like shape. (Also, I zoomed in a little with the mouse wheel. That’s just the edit view; it doesn’t affect the model).

From an angle (middle mouse button to tilt the view):

Hit Numpad 7 to return to top view. We’ll need the control points a little closer to the center of the blade to make the blood groove later. We could mess around with moving them individually, but let’s do it in bulk: Hit a to unselect things, and b to box select the ones as shown below. (Remember, you’re also selecting all the ones in the depth along the Z axis this way).

Hit s to scale them, and x to only scale that axis, sliding the vertices toward their center on just that axis:

Now, at an angle, we’re up to something like this:

Obviously, we need to sharpen the edges. By default, the subsurf'ed mesh follows relaxed, smooth curves, but you can "crease" edges to make them sharper where you need it, forcing the mesh to conform tighter to the control cage. This balance between the smooth nature and the creased edges is the secret behind subsurf modeling.

So let us edit an edge. Alt + right-click on a line in the mesh to select the entire edge loop. (Which in this case is not much of a "loop", just an edge along the length of the cylinder).

With the edge selected, hit Shift-E, and drag out the edge to maximum sharpness. Do this with both sides.

Now we need to do the tip. Select the bottom loop with Alt + right-click (this time it actually looks like a loop, running around the cylinder), and his s to scale. Type 0 and hit Enter to instantly scale to zero.

The other end looks a little weird, with the way it curves inward. Remember, by default, subsurf does its best to make things smooth, but we really want a sharp edge here as well, even if it is a "corner to nothing".

So select the top edge loop (Alt + right-click again), and crease (Shift+E) it to maximum sharpness.

Now we are getting somewhere. Go to front view (Numpad 1), zoom a little out (with the mousewheel) to get some working space, hit a to deselect and a again to select everything.

Hit s to scale, and z to lock the scaling to only the Z axis, so we can drag out a proper length for the blade. (You may need to do this in a couple of steps if your mouse hits the edge).

This is starting to look like something. Take a moment to lean back and spin around the object with the middle mouse button. Call this resting, recharging and enjoying the fruits of your work. (Also, this reveals any screwiness which may have been hidden from the angles we've worked from so far, but shhh..., don't tell anybody we may have screwed up).

For fun and education, try hitting z to switch to wireframe view, and notice how the actual faces of the mesh are nicely distributed. (You can even try to drag some control points around to see how things react. Just undo with Ctrl + z).

We still need the blood grove, though, so let us turn our attention to those middle vertices we temptingly left near a cluster of other vertices at the very beginning.

Hit z to return to solid view, and Numpad 1 to go to front view.

We don't want the grove to start at the very tip, so hit a until you're sure nothing is selected, and let us use box select, b, to higlight an appropriate range. Be careful only to catch the middle column, not the ones beside it, and select the upper 7 vertices. Remember, we are selecting "through the mesh" as well, selecting the vertices on the other side too, which is what we want.

Now, zoom in and tilt the view a little to give a good, shaded view of what is going on, and hit s and y to scale along the Y axis. This way you are scaling along the world Y axis, no matter how your camera is rotated. Scale the middle vertices towards the center this way, carving out the groove.

You may want to crease this edge a little while you have it selected, to make the grove more pronounced. (Or, rather, these edges, since we also have the backside). So do that with Shift + E if you want.

You probably want to crease the edges beside the grove a little as well, so return to fron view (Numpad 1) and select those.

...and returning to a good view, we crease these edges to turn it into an aesthetically pleasing murder device.

There is still a detail to touch up. We left the last edge loop before the tip entirely untouched, so it still has the original look of the flattened cylinder, which bulges out compared to the rest of the blade. So let us move down to that area (Shift + middle mouse to pan the view), and get a good look at the vertices there. Select the two offending ones. We could do this by switching to front view and box selecting them both, but since it's just two, it's easier to just pick them out where they are. Right-click one to select it, and then Shift + right-click the other to add it to the selection, like this:

Now do the usual scale along the Y axis, s, y, and slide the vertices inward until it looks good:

 

That's it for now. I'll leave hilt and crossguard as an exercise for yourself. But here's a hint: Surbsurf'ed cylinders.

Also note that we have a lot of control points along the length of the blade, which can be used for creative embellishments, such as curving the blade, or even drawing out and creasing dangerous-looking spikes and edges, in the good old fantasy style.

Here is the blade inworld, with just a blank texture with medium shininess.

And as examples of embellishments you can do, here are some blades made with this technique.