Why render with no anti aliasing? Are you using color key for your transparent color? Can't you use and alpha map? Which 2d renderer are you using? Try Gapi draw (www.gapidraw.com). Best2d renderer in the industry, does super fast alpha and IS FREE with no license agreement. Just mention them as the renderer. Try rendering real big, reducing with anti alias then select around the figure and set that to your chromakey color. You'll still get hard edges but the interior will be smooth. Pick a nuetral color for rendering on like grey or blue or green. Grey is good since it doesn't leave a funky blue or green halo around the figure when antialiased.