This tool will calculate a dynamic Data window or a crop mask inside of Houdini's stage or Solaris context. Similar to the "Crop Mask" found on standard Houdini Cameras. This can save render time from 3D but also save time and file size while you're compositing in Fusion or Nuke. See the video and find out more about this tool here:
This HDA was created in Houdini Indie. If you have a HoudiniFx or Houdini Core license you have to rebuild this tool yourself. I’m currently trying to get it available for all Houdini versions through Orbolt.
The Calculate Data Window HDA