try gimp
http://www.thinkall.com/product_image_over8.htm
http://www.gimp.org/downloads/

and try Blender for 3d

nice spaceships :)

http://en.wikipedia.org/wiki/Game_Blender is all I can find out. I'd like a more in-depth comparison between gmax and blender myself but I guess gmax is already good enough for me.