Starting from prman 14, it's been introduced a new rerendering method, similar to IPR.

I was doing some research on how to implement this in Houdini, but reading the Houdini journals update log, I found out that this:

Wednesday, May 21, 2008
Houdini 9.5.113: The renderman display driver has been modified to use a slightly newer version of the imdisplay protocol. It will not work with older versions of Houdini (i.e. prior to 9.5.113).
However, without the newer driver, the mplay driver will not work correctly with prman 14.0 re-rendering technology (which is not yet supported in Houdini).

I was wondering how are things now.

Thaks,
Fabio/