Making lense distortion in Maya

here is a brief explaination of how i contstructed a convex lense distortion in maya:

Step1: create a nurbs semi-sphear and give it a reflective blin, with ray tracing

Step2: position a camera so it is looking inside the semi sphear (close up)

Step3: for this example i used text moving behind the camera which reflects in the semi sphear and therefore distorts

Step4:: i renderd out on 1k square tiffs  a sequence which i then used as a texture with image sewuence on a blinn or phong e, i forget. offsetting the image sequence lets you position the lense distortion when you need it on the time line.

It took me days to figure this one out so i hope this helps others with the same problem. :)