Nope, sorry, currently only texture from files are supported by the Octane plugin. I've in my TODO list make some research about this limitation, to know if I can have access to the RAW image data from the Houdini HDK to get the COP nodes texture data and feed the Octane texture node with it. I'll let you know if I find a way to support this feature.
Computer Graphics Software Developer
Octane plugin development and support: LightWave and Houdini