EMERYVILLE, Calif. -- The two main characters of "Wind," the latest short released from Pixar's innovative SparkShorts program, are a grandmother and grandson who live on giant rocks, are trapped in an endless hole and are working together to find a way out. They represent the grandmother and father of the writer and director of "Wind," Edwin Chang.As with other shorts created within the SparkShorts program, which allowed a diverse group of creators to tell their stories their way, "Wind" is deeply personal."It was inspired by my grandmother," Chang explains. "She was a single mother after the Korean War, and it's inspired by everything she did take care of her kids and my dad, feed them, educate them and eventually sending them all the way to the U.S. for a new life."The story is a metaphor for immigration. The setting for "Wind" is a little dark and post-apocalyptic with a sense of urgency to try to escape the current surroundings. But there's a sense of optimism and love between the two characters that infuses the short with a sense of family and hope.For "Wind" producer Jesus Martinez, Chang's story is also relevant to the current immigration debate."We were making this last year where the situation at the border and the refugees that were being held up there," Martinez describes. "It kind of flared up, and it was just kind of one or two sides of the story that we're being told. So for me, it was so important to sort of put a different perspective out there of showing that these decisions are never easy. And they're both full of fear and hope at the same time."Chang's grandmother passed away before the film's completion, but in many ways "Wind" is part of her legacy. It would never have been possible without her sacrifices. When asked what his family thought of the film, Chang said they loved seeing their grandmother represented on the screen. And what would Chang's grandmother have thought?"The main source of her joy was taking care of her children and making sure that they were thriving. And so, I think, for her to see this and see how her children and her grandchildren have done and I think that would make her really happy."