When you start exporting from Blender to Collada format, you’ll notice that several techniques that should work simply don’t work. You have to use several tricks or special methods to make sure that everything is exported without any problems. Patrick worked for 2 months to make sure that animations, materials, and other elements of the scene are exported correctly from Blender to Collada format. He has written several step by step tutorials and has shared his valuable experiences:
Hope these tutorials come in handy.