Software such as Blender (www.blender3d.comlcrns/Home.2.0.html), for modeling and animation;
Qcad (www.ribbonsoft.com/qcad.html), for computer aided 2-D drafting; the GIMP (www.gimp.org/), for image manipulation; and ImageMagick (www.imagemagick .org/script/index.php), for creating images from scratch may be able to replace expensive imaging software.