Brent Renaud, an acclaimed filmmaker who traveled to some of the darkest and most dangerous corners of the world for documentaries that transported audiences to little-known places of suffering, died Sunday after Russian forces opened fire on his vehicle in Ukraine.The 50-year-old Little Rock, Arkansas, native was gathering material for a report about refugees when his vehicle was hit at a checkpoint in Irpin, just outside the Ukrainian capital of Kyiv. Ukraine's Interior Ministry said the area has sustained intense shelling by Russian forces in recent days.Renaud was one of the most respected independent producers of his era, said Christof Putzel, a filmmaker and close friend who had received a text from Renaud just three days before his death.