The project was recently featured on Prosthetic Knowledge, but the technique is anything but an overnight success. His technique is really a combination of several techniques: first, they scanned Flickr for 100,000 portraits. Manually, they trained the computer, by marking hair segments—basically, the chunks of your hair like parts that will dictate how the strands flow down your scalp. Modeling the growth of individual strands of hair from these segments, researchers can make some level of guess about how the total head of hair looks.
The problem with just doing this, says Chai, is that “it often generates results that are too smooth and flat, especially at the back.” Hair flow isn’t synonymous with hair style—the cuts and curls that really make hair look fashionable. So this segmentation and hair grown information was essentially cross-referenced against hundreds of 3-D hair models from The Sims, which gave the back of someone’s head a bit more flare.
