I have compiled the Arnold lens shader for Oculus rift for Autodesk Maya. I just followed the instructions from Solid Angle. Below is the download of the shader files along with instructions on how to use it.Download Arnold Lens Shader for Maya - Oculus rift
Here is the code that was used to compile the above lens shader https://support.solidangle.com/display/mayatut/Creating+a+Basic+Spherical+Camera .
I have included the visual studio project file here , since we might be using different versions of arnold SDK, I only have included the oculus files into this project.Download Visual studio Project files
In order to use the above project file : First download the arnold SDK from https://www.solidangle.com/arnold/download/ ,then open the visual studio project file and change the include and library paths in the property pages. Once this is done , try placing the DLL file in the appropriate folder and check inside Maya.
The MtoA version I am using is 184.108.40.206 , the Arnold SDK that I used to compile the DLL file is 220.127.116.11
Let me know if you have any questions.