For open source MOPs release notes, please see the Releases page on GitHub.


  • Added “Pulse” function to MOPs Waveforms.
  • Fixed a bug in MOPsDOPs Apply Attributes that mistakenly set id attribute -1 in Vellum and other particle simulations.
  • Fixed Python3 compatibility in MOPs Shape Falloff DOP.
  • Made several changes to MOPs RBD Runtime Constraints:
    1. The Mask parameter now requires both objects involved in an impact to be included in the Mask for a collision to register. This excludes static objects like Ground Plane DOPs.
    2. The constraint orientation is now based on the p@orient attribute instead of the transform intrinsic. This should result in more stable orientations on impact.
    3. This DOP can now differentiate correctly between multiple DOP objects in collisions.


  • Added MOPs RBD Runtime Constraints DOP.
  • Added MOPs Waveforms.
  • Added example files for the two new operators.
  • Fixed a bug in MOPs+ Combine Falloffs that prevented DOP Falloffs from functioning in Python3 builds of Houdini.


  • Scaling in both local and world space, with support for the mops_orient attribute, now works properly in MOPs+ Apply Attributes DOP, to match the recent changes to MOPs Apply Attributes SOP.
  • Fixed a bug that caused Houdini to crash while collapsing MOPs+ Typography into a subnet in Python 2 builds of Houdini.
  • Fixed the “Inside”, “Outside” and “Surface Distance” modes on MOPs+ Object Falloff DOP.


  • Added MOPs Fetch Attribute DOP.


  • Fixed a bug in MOPs Typography and MOPs Edit that prevented compatibility with Python 3 builds of Houdini.
  • Fixed a bug in MOPs Typography that caused letter index attributes to be generated incorrectly with multi-line text imported from a file.


  • Refactored all Python code for Python 3 compatibility. Note that this change will cause the stored table data in MOPs Attribute Mapper to be invalid. You will need to repopulate any MOPs Attribute Mapper tables. Apologies for the inconvenience.
  • Fixed a bug in the Activation process that threw an error if the button was clicked outside a SOP network.


  • Fixed an unlikely bug in the Apply Attributes DOP that could break snapping behavior.
  • Fixed bug in activation that threw an error when trying to re-activate an activated license.
  • Clarified activation procedure.