It is there any way to export the foam data generated from ocean modifier to use it in other render engine, like LuxRender? The manual says that the foam data is stored as vertex color data, but there isn't a way to access the vertexColor data. I know that can be accessed from Cycles from attribute's node. LuxRender supports vertex color and I tried to bake the texture to vertexColor and an image but only get a plain black texture.
Finish settings for ocean such as wind, choppiness, etc.
Set resolution in ocean modifier. For example, 16 will result in a baked image 256x256 pixels. 64 is the largest, final baked image is 4096x4096.
Check the boxes for generate normals and Foam,
Set cache path anywhere you want (should be an empty folder) and bake.
After a while you get images like this one in your cache folder: