I tried one. As I recall, the examples were gigantic, they expected scenes to be described in XML, and it took an hour to compile. It looked cool in demos, but

I tried one. As I recall, the examples were gigantic, they expected scenes to be described in XML, and it took an hour to compile. It looked cool in demos, but there was no way to get a foothold on it as a library. I never got it to do anything useful. I only made modest progress by implementing a custom XML tag that let me get my data into one of their huge example programs. I'm a better programmer now than I was then, but I still kinda think that software sucked.