Last week I got a fresh sense of the business potential for Second Life, the immersive 3D world created and maintained by San Francisco-based Linden Lab. But my epiphany didn’t come while talking to the Linden Lab folks. Rather, I was chatting with Carl Bass, CEO of Autodesk (ADSK).

If you’re not in the design or construction businesses there’s a good chance you’ve never heard of Autodesk, even though it’s a $9.8 billion market-cap Silicon Valley software company with revenues topping $1.5 billion in 2006. Autodesk makes the digital tools that replace the architect’s drafting table; think of it as Adobe (ADBE) Photoshop for design engineers. Construction companies, car designers and toy creators use it; the company even has a unit that caters to Hollywood special effects artists. Bass says lately, much of Autodesk’s business is helping to create “digital prototypes” – virtual versions of products and environments that let customers feel like they’re trying out the real thing.

So it made sense that Bass was more than a little pumped up when I met him Wednesday afternoon at Autodesk’s San Francisco office. By chance, he’d just eaten lunch with the co-founder of Linden Lab, the originators of Second Life. Bass said they talked about ways the two companies could collaborate, and there were scads of possibilities. “I came out of it excited, saying, ‘How do we get stuff from this world into another use?”

From the looks of things, it will be pretty easy. Bass says Autodesk’s 2D software business still provides the bulk of its revenues, but 3D software sales are growing twice as fast. New customers in emerging markets such as India and China are going straight to Autodesk’s high-end 3D offerings, rather than starting with 2D and working their way up. And once those designers have made 3D prototypes with Autodesk software, they can use those prototypes to create structures in Second Life that virtual residents will pay real money to own.

I could see even more scenarios. Companies that make car and airplane parts use Autodesk software to create renderings of the tiny components that fit together to make an engine or a transmission. Those 3D renderings could be imported into Second Life, and animated. Before long, Second Life cars wouldn’t just be blocks of pixels rolling down a street; they’d be more like the real thing – collections of nuts and bolts and gears that can break down or get suped up.

And that’s just the beginning.