In addition to my writing duties at the Tonight Show and elsewhere, I am also responsible for many graphical elements for the show. It’s pretty interesting and diverting to go between these different tasks, and the most fun is finding an excuse to model something in 3D. But then those models or characters only end up existing for the brief time that the graphics are up.
But now, I can print them out.
I thought I’d take a shot at a couple of busts (insert joke here). Sitting across from Kevin Smith in his office, I am surrounded by these fantastic sculptures of comic book characters in action, so I decided to go for that very expressive, not-entirely-realistic style. While there are all sorts of software packages that allow you to sculpt virtual models, and even tools within Maya (the 3D animation package I use), I like Autodesk Mudbox. I opened it up and started with a base model. They even color it to look like clay:
I won’t get into all of the gory details on sculpting, but suffice it to say there are tools that let you cut, smooth, push in, pull out and foam up the surface. After about a half an hour I came up with this:
I had to export the model into Maya to add some geometry for the teeth, and of course I left the goggles separate from the model, so I just accentuated the area around the eyes and the upper cheekbones, to give the impression that he was actively looking through them. Then I imported the model into Maya and added the goggles, putting in some neck bones so I could pose the head, looking off to the right and up. That way, when the model is sitting on a desk, you can aim it so it’s looking at you.
From here, it was easy to export the model as an .stl file (short for Stereo Lithography, a standard 3D printing file format), and bring it into the printing software. I opted to print it as a hollow shell, about 2mm thick, to save on printing filament, and used support material as an option (support material is like a very thin scaffolding, so that when part of the model is cantilevered out, the machine doesn’t have to print into thin air, like under the nose). Once the print is done, you just pull it away and clean up any leftover nubs with an X-acto knife.
The polishing process is interesting, but hard to photograph. You take a coffee can, put in a few teaspoons of acetone (like in nail polish remover), then put it onto the heating bed of the 3D printer. While that heats up, you chill down the model. Then, when the acetone has evaporated (it has a low evaporation temperature) you suspend the model in this “vapor bath.” The cool model causes the vaporous acetone to condense on its surface, and the presence in the vapor bath keeps it from evaporating right away. This makes the lines of the 3D print melt – ever so slightly – into each other, making the surface smooth and polished.
You can also sculpt using photographs in Mudbox, basically pinning them up behind the model as reference. I used a fashion model I found online who looked a bit cartoony, with huge eyes and lips and a very long neck, to make the following computer model:
In the shot below, you can see that I was running out of acetone, so the polishing effect on the surface did not develop fully, and you can still see the horizontal lines of resolution from the printer.
Next up I’m going to pull the airbrush out of mothballs and see if I can paint the damned thing. Looking around on the web, I see that some guys use acrylic paint, and actually paint their models before polishing. The action of melting the surface keeps the paint from scratching as easily.
Of course, there are color 3D printers out there, but they cost a lot more than the 500 bucks mine did.