Computer Scientists Create CG Sand That Looks Unbelievably Real

Computer generated graphics take hours of fine tuning to get the image to look "realistic." Film studios spend millions of dollars investing in the latest CG technology, all so no one watches one of their movies and says "That looks so cheap!"

Particular aspects of nature prove especially challenging for artists. When Pixar created Brave, the CG artists spent two months getting Merida's signature curls just right. Disney did something similar for Rapunzel's long hair in Tangled. While hair seems to be getting on the right track compared to the perfect coifs of old animation, certain elements are still lacking.

One of the biggest struggles is sand and mud in CG films. Sand by itself is becoming more believable. New short films from Disney and Pixar showcase the strides made in sand movement, particularly with the Oscar-winning short Piper.

Combining the two substances proves more of a challenge. A team at UCLA partnered with animators from DreamWorks, Jixie Effects, and the University of Pennsylvania to find a solution. It required them to figure a way to perfectly capture the snowball effect of a mudslide. The researchers also used varying densities and strengths of water.

Chenfanfu Jiang serves as an assistant professor in UPenn's Computer and Information Science Departments. He said that the novelty comes in how water moves and interacts with the sand.

"Technically, we use particles to represent individual grains of sand and water droplets," he said in an interview with Gizmodo. "In each simulation time step, individual material responses, as well as the interaction force between sand and water, are computed."

Via: Chenfanfu Jiang