If you didn’t believe me before, check this out. This was done with Blender, which was a commercial app until 2002 when the company who created it went under. They then offered anyone to buy the source code, and the open source community ponied up — to the tune of $147,000 US. Six years later, the code is improved to the point where it can create stuff like this. And I dare you to tell me this is any less than Pixar quality.
Big Buck Bunny from Blender Foundation on Vimeo.