This is a general information thread about MOPs: Motion Operators for Houdini. I'll post updates here as well when new patches are released.

What's MOPs?

Video courtesy of Paul Esteves

MOPs is a motion graphics toolkit for Houdini. It's a collection of HDAs (custom nodes) that are meant to make common motion graphics tasks such as local transformations, moving on paths, masking operations, and more much easier. Though MOPs is primarily a tool for motion graphics, it's also used by many VFX companies large and small to make traditional FX work easier. MOPs operates entirely natively within Houdini and is not a closed system, and can be used interchangeably with native SOPs. MOPs is free and open source, and always will be.

You can get MOPs on Github here: https://github.com/toadstorm/MOPS [github.com]

What's MOPs Plus?
MOPs Plus is a commercial, closed-source add-on to MOPs. It has a number of higher level tools for things like typography and cameras, and also extends the MOPs toolset into DOPs so you can better direct particles, RBDs, and Vellum simulations. MOPs Plus is a permanent license; yearly payments are for updates, not for the software license itself. You can pause the subscription at any time if you don't want or need to update.

You can create an account and purchase MOPs Plus here: https://www.motionoperators.com/info/mopsplus/ [www.motionoperators.com]

Where can I get more information about MOPs and MOPs Plus?

• The MOPs homepage [www.motionoperators.com] has a number of useful links.
  
• The MOPs Wiki [github.com] on GitHub has an overview of every single node in MOPs and MOPs Plus, installation guides, and more.
  
• The MOPs Discord server [discord.gg] has a growing community of users that can offer help quickly.
  
• There's a MOPs phpBB forum [forum.motionoperators.com] for people who prefer that format.
  
• This presentation [www.youtube.com] from May 2020's Houdini HIVE gives an overview of what MOPs does and has some sample scenarios.
  
• There's an in-progress free tutorial series on MOPs Plus [www.youtube.com] that's also a good way to get an overview of the new tools.
  
• Or, just reach out and ask me! You can contact me at henry@motionoperators.com.
  

A new release of MOPs Plus is now available!

This adds the following fixes and changes:

• Added "Goal" mode to MOPs Curve Toys. This attracts curves towards a goal position.
  
• Added a new example file to demonstrate the updated MOPs Curve Toys node.
  
• Fixed the group mask selector for all modes in MOPs Curve Toys.
  
• Added MOPs Waveforms v1.1. This changes the "Time" parameter to "Cycles" for easier looping.
  
• Fixed a definition problem with MOPs Edit that prevented the new v1.1 from being accessible. You can now edit pivots with MOPs Edit (press the apostrophe key while in the tool state to activate).
  

MOPs Curve Toys Goal mode demo:


MOPs Edit pivots demo:

New updates are now available for both MOPs and MOPs Plus.

MOPs 1.7.6 Experimental fixes some minor bugs with the Instancer and adds support for File Cache SOPs as direct inputs.
MOPs Plus 2022-10-26 adds several new UX improvements to MOPs+ Physics Edit, a quasistatic Bullet solver (think Vellum Brush, but for rigid bodies).

You can download the latest MOPs release here: https://github.com/toadstorm/MOPS/releases/tag/v1.7.6e [github.com]

The full MOPs Plus changelog is available here: https://www.motionoperators.com/changelog/ [www.motionoperators.com]

Here's a quick preview of the updated MOPs+ Physics Edit handle in action:

New updates are now available for both MOPs and MOPs Plus.

MOPs v1.7.7 Experimental patches some behaviors in MOPs Apply Attributes related to the `p@mops_orient` pretransform attribute created by MOPs Reorient. All MOPs nodes will now correctly output `p@orient` relative to the value of `p@mops_orient`, if it exists, and interpolation between transforms with a `p@mops_orient` attribute should now blend correctly. Alembics wired into MOPs Convert will automatically extract the `packedfulltransform` intrinsic and apply it to `p@mops_orient` for correct local transformations. You can download the updated release here: https://github.com/toadstorm/MOPS/releases/tag/v1.7.7e [github.com]

MOPs Plus build 2022-12-27 updates the MOPs+ Edit SOP to correctly orient the transform handle based on the `p@mops_orient` attribute, and fixes a couple of minor bugs with MOPs+ Sequencer and MOPs+ Camera Blender. The full changelog can be viewed here: https://www.motionoperators.com/changelog/ [www.motionoperators.com]

A new experimental update to MOPs is now available: https://github.com/toadstorm/MOPS/releases/tag/v1.7.8e [github.com]

MOPs v1.7.8 Experimental adds the following changes:

• Patched a bug in MOPs Apply Attributes that caused points without packed transforms to reset their scale and/or pscale attributes in some operations like MOPs Randomize.
  
• Added warning to MOPs Spread Falloff when points are outside the connections network. These points will no longer be affected by the spread.
  
• The MOPs Noise Modifier now initializes the scale and pscale attributes when generating trails if those attributes don't already exist.
  

New builds of MOPs and MOPs+ are now available!

MOPs v1.7.9 Experimental patches a number of bugs with MOPs Apply Attributes and adds the ability to extract 4@xform into individual template point attributes. Release page: https://github.com/toadstorm/MOPS/releases/tag/v1.7.9e [github.com]

MOPs+ 2023-02-23 adds new Volume Falloffs to the mix! Shape Falloff Volume and Object Falloff Volume can apply simple falloff functions to fog volumes, heightfields, and velocity volumes, complete with seamlessly looping noise and lots of compositing modes. MOPs+ Apply Attributes DOP can now choose goal attributes based on the nearest point on a surface, too! Great for applying goals with changing point counts or particle fluids. Full changelog: https://www.motionoperators.com/changelog/ [www.motionoperators.com]

A new stable release of MOPs, v1.8, is now available: https://github.com/toadstorm/MOPS/releases/tag/v1.8.0 [github.com]

This update includes all experimental updates released since 1.7.1, and includes numerous bugfixes and improvements to the core API nodes.

A new build of MOPs+ is now available! This introduces the MOPs+ Infection Falloff solver, and fixes some bugs in MOPsDOPs falloffs. Details in the changelog: https://www.motionoperators.com/changelog/ [www.motionoperators.com]

A new MOPs Plus is now available! This adds new features to Infection Falloff, improves site licensing options, and tidies up a few other nodes. Details in the changelog: https://www.motionoperators.com/changelog/ [www.motionoperators.com]

A new Experimental release of MOPs, v1.8.1e, is now available. This makes Shape Falloff in Fan mode transform correctly when falloff is negative, and MOPs Convert now repacks incoming Alembics for more consistent pivot behavior.
https://github.com/toadstorm/MOPS/releases/tag/v1.8.1e [github.com]

A new MOPs+ tutorial video is out! This video focuses on using MOPs and MOPs+ to influence Vellum simulations.

This coincides with a new MOPs Plus release that contains updated Vellum example files and some quality-of-life improvements to Falloff DOPs and the Fetch Attribute DOP. Details on the changelog page: https://www.motionoperators.com/changelog/ [www.motionoperators.com]

Forgot to post this update here last week. A new build of MOPs Plus is now available. This introduces the first MOPs+ Rig nodes, aimed at integrating MOPs tools with KineFX. Here's the full changelog:

• Added the first MOPs+ Rig nodes: MOPs+ Rig Falloff, MOPs+ Rig Transform, and MOPs+ Rig Noise.
  
• Added new example file, mops_rig_nodes.hip
  
• MOPs+ Trigger Falloff now has an option for a “threshold attribute” that can vary the trigger threshold per-point.
  
• MOPs+ Camera Blender now has a menu script for Extra Attributes to quickly pick extra attributes to interpolate or bake.
  
• Fixed a bug in MOPs+ Camera Blender that prevented single Extra Attributes from baking.
  
• MOPs+ Typography now always corrects the facing direction of outlines to face +Z.
  
• The minimum Python version for MOPs Plus is now 3.7. MOPs Plus is now built on Houdini 19.0.657 as a minimum version.
  

New releases of MOPs and MOPs Plus are now available!

MOPs Experimental v1.8.2 fixes a bunch of bugs related to MOPs Instancer, MOPs Extract Attributes and MOPs Apply Attributes. The full changelog is available on the release page [github.com].

MOPs Plus introduces more MOPs+ Rig nodes: Rig Spring, Rig Resample, and MOPs to KineFX. Rig Spring applies spring forces in local space to joint transforms. Rig Resample inserts new bones into skeletons and seamlessly adds them to the skin weights without disturbing the existing weights. MOPs to KineFX converts packed primitives into captured KineFX geometry for easier keyframed animation. The full changelog is available here [www.motionoperators.com].

Forgot to post this earlier upon the new release.

MOPs v1.9.0 Stable is now available on Github. You can download it here [github.com]. Highlights include:

• MOPs Delay and MOPs Spring now allow for new points to be introduced mid-simulation
  
• MOPs Convert now repacks Alembics by default, so their transforms behave more like regular packed primitives
  
• MOPs Visualize Frame visualizer has been improved, now more stable and lightweight
  
• MOPs Apply Attributes now correctly deals with mops_orient when falloff is zero
  
• Fixed bugs in MOPs Extract Attributes that incorrectly modified N and up if "Extract MOPs Orient" is enabled but doesn't exist
  
• MOPs Explode now removes most temp attributes prior to packing
  
• The sequence cycling attributes in the MOPs Instancer now match those of MOPs Set Sequence Time, default cycling behavior fixed
  

A new release of MOPs Plus is now available! This improves Rig Resample, adds new features to Velocity Field and Camera Blender, and most importantly, adds the Font Browser to MOPs Typography! Details on the release page: https://www.motionoperators.com/changelog/ [www.motionoperators.com]

Here's the new Font Browser in action...