Blender has had a sculpt mode for a while now, but with the recent release of the ground-up recode 2.5, a few minor tweaks have made it into a really powerful tool, especially for people looking to interact with their 3D in a more intuitive way than painstakingly dragging vertices around and fretting over topology. In this tutorial, we’ll start with Blender’s default cube and carve numbers into it!
For this tutorial, you’ll need to go grab the latest release of Blender 2.5, which is still in alpha but stable enough to work with. It’s a well-behaved zip file– just dump it in a directory and run the executable.

Pretty different from 2.4x, huh? Not to worry, the stuff you’ve learned so far (hopefully you still remember when I used to do tutorials on a regular basis) still applies. Some windows are moved around, but the modeling stuff is still mostly where it was in 2.4x, and the shortcuts haven’t changed.
Sculpt mode performs a lot better on a mesh with some amount of detail to it (IE, 50 or more faces), so our first step will be to subdivide the cube. Hit tab or select edit mode from the mode dropdown. One thing you’ll notice is that the buttons on the left side of the screen change: this is the new-for-2.5 Tool Shelf, and it’s context-sensitive, which is pretty keen. For our purposes, it’s just good that you can see this:

Click subdivide. You can either adjust its settings in the panel that appears below or hit it again to get a subdivided cube that’s ready for sculpt mode:

You can use any sort of mesh as a starting point for sculpting. I’ve uploaded a few additional start points, but sculpt mode can be used on just about anything, including imported models from other programs!
Go down to where the window says edit mode and switch to sculpt mode:

The Tool Shelf responds to this by morphing into a sort of paintbrush window– this is sculpt mode. With the low-resolution mesh we started with, it’s kind of hard to sculpt much of anything, but the tools should already work:

To get really nice results though, we’ll need more polygons. It’s time to revisit the Modifier Stack. Over on your right you should see the properties buttons. Click the wrench:

And select add modifier below:

Select Multiresolution. This tool works well with sculpt mode and allows you to hop back and forth from higher to lower resolution versions of the same model. This can be handy when you’re trying to optimize for performance. (For example, knocking down the subdivision will make something skin a LOT faster in skeinforge.)

Hit subdivide a few times. I went with 3 times, but you can go higher or lower, depending on how much detail you want to carve (and how fast your computer is!) You should now have a pretty smooth looking cube:

Notice how the edges have been rounded off. Subdivision in Blender tends to smooth everything out.
Now, enough fiddling with settings, let’s sculpt!

These controls should be pretty self-explanatory– size makes a bigger brush, strength increases or decreases its effect. Add/Subtract lets you reverse the effect. At this point, feel free to experiment and create your own shapes– this is definitely the fun part of this tutorial!

One feature you could miss: if you scroll down on the tool shelf you’ll find a group of symmetry locks, which can be really handy when sculpting animals, which tend to have bilateral symmetry.
I took a size 25 strength .5 draw brush and in subtract mode carved numbers on the faces of my cube:

When I switched into object mode, all my sculpting seemed to disappear, though! After a bit of worrying, I looked at the modifier stack (still on the right side of the screen):

With the Preview button set to 3, I could see my detail from object mode. Next I went to the export option:

Blender 2.51 doesn’t come with an export to .stl yet, but .obj works with a lot of other 3D programs, including earlier versions of Blender. We also just sculpted this at a width of 2mm, so following Bre’s tutorial on resizing objects at this point may be in order anyway.
Hopefully this all made sense, and if there’s any confusion, let me know in comments and I’ll see what I can do!
