So I guess it has become obvious from our game title that we here at Skull Theatre like rust. We like the way it softens the edges of man-made objects and blurs the line between things that have been manufactured, and organic objects that have been grown. We especially like the surprising array of colors that bloom out of the iron it is consuming- deep red, vibrant orange, eggplant purple, black. But before I wax too poetic, let me just say that it also 3D Captures really really well. Our engine loves texture and color variation and rusty bits are right up its alley.
As you’ve seen in previous posts, we’ve had a nice amount of success with scavenging for rusted metal objects around Seattle (I found a great rusty pipe on a hike on the Dungeness Spit a couple weeks ago) but many of the objects in our game, such as the robot characters, and buildings, still need to be built by hand, and its important to make sure that their appearance meshes well with the real-world rusted objects that we have scanned. That’s where I come in.
Most of the objects that I construct are made from paper mache and clay (its cheap and its light-weight!) so a faux metal or rust look needs to be achieved through creative painting techniques.
We can author the gloss map of a scanned object to appear metallic but since Im a classical artist and am more comfortable working with real-world textures, I prefer to use a metallic paint ( the metallic appearance is preserved through post processing of the gloss map). There are many excellent tutorials on the web on how to combine colors to achieve a rusted look, but Im stubborn as hell about learning on my own through experimentation whenever possible. I’ve found that a base coat of iridescent bronze blended with burnt umber and mars black, with highlighting/detailing in iridescent bright copper and Golden’s wonderful Micaceous Iron Oxide work quite well for most of our objects.
The downside of using metallic paints, and acrylic paints in general, is that the painted object we’re trying to capture tends to be quite shiny, and 123D Catch doesn’t like that (it really needs that stable lighting environment without reflections to function properly) so I brush everything with a fine coating of powder to matte things up a bit, before we start photographing.
Hold up, you’re saying, isn’t there a technique out there where you can paint with a substance that contains actual iron and then brush an oxidizing medium over it to create REAL rust? Yes, yes there is, and I bought it, but I was so frightened by the lengthy health and safety warnings and the incredible smell (imagine the scent of a thousand rotting shellfish covered in gasoline) that I have only experimented with it once, so stay tuned on that. If I can gird up my loins to approach this foul sludge once more, I will post about the results.
In the meantime, Im still new to all of this so if there are any model makers/painters out there who have discovered some great techniques for mimicking rust or metal, please share!