Shares of 3D Systems (NYSE: DDD), a 3D-printing company, were falling today after it reported first-quarter results. 3D Systems reported a non-GAAP loss of $0.06 per share in the first quarter, which was worse than analysts' consensus estimate of flat earnings for the quarter. Investors were likely very disappointed with the loss not only because it missed Wall Street's expectations, but also because 3D Systems reported non-GAAP earnings of $0.17 per share in the year-ago quarter.