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MOPS WIKI DOCS

MOPs (Motion OPerators for Houdini) is a set of tools for SideFX Houdini that are intended to simplify and automate common motion graphics processes in Houdini.

MINIMUM REQUIREMENTS

Houdini 16.5 or higher (any license type)

MOPs Plus requires Houdini 18.0 or higher (any license type).

Important: Houdini 18.5 builds after 18.5.351 have an error that prevents packages from loading properly. If you are using Houdini 18.5, you must either download build 18.5.415 or later, or use the Houdini.env installation method.

INSTALLATION

See Installation for install instructions.

BASICS

See Basics for an overview of what MOPs does and how it works.

TUTORIALS

  • See MOPs Tutorial for an in-depth tutorial series on the MOPs system.
  • The Houdini Hive Worldwide presentation has a good overview of what MOPs does, and a number of detailed use cases showcasing various parts of the MOPs system.
  • For information on the new MOPsDOPs system in MOPs Plus, see MOPsDOPs Tutorial.

NODE LIST

The following is a list of all MOPs nodes you can use. For detailed help per-parameter, consult the internal Help page for each node. These links are just for a general usage overview.

IMPORTANT: Nodes flagged as "(Plus)" are part of MOPs Plus, the commercial add-on package to MOPs. To view the new MOPs+ DOP context nodes, see MOPsDOPs.

These are Object-level nodes that don't fit in with the rest of the SOP-focused toolset.

MOPs Camera Blender (Plus) - Blends the transforms of multiple cameras together smoothly, and optionally adds camera shake, physics, and composition guides.

Generators create geometry, either polygons or packed primitives ("instances").

MOPs Convert - Converts geometry or standard packed primitives into MOPs-compatible packed primitives, with all the necessary point attributes.

MOPs Explode - Breaks the individual faces of a polygon into MOPs packed primitives.

MOPs Greeble (Plus) - Recursively subdivides and extrudes polygons to make rectilinear details.

MOPs Instancer - Creates and arranges copies of things.

MOPs Sequencer - Generates attributes rhythmically using a tracker-like interface.

MOPs Subdivider - Divides and rotates polygon faces.

MOPs Sweep Spline - Turns curves (splines) into polygons, with many output options.

MOPs Trails - Generates stable polyline trails from input points or packed primitives, with lots of customization options.

MOPs Typography (Plus) - Generates letterforms or processes vector art with easy controls for bevels, chisels, alignment, kerning, and more.

Falloffs create or modify the f@mops_falloff point attribute, which modulate the effects of Modifiers (and some Generators) downstream.

MOPs Audio Falloff - Uses defined frequency bands of an audio file to create falloff from sound.

MOPs Combine Falloffs - Composites the falloff attributes of two nodes together.

MOPs Falloff From Attribute - Remaps an existing attribute (such as i@id) into falloff.

MOPs Noise Falloff - Uses various noise patterns to generate falloff.

MOPs Object Falloff - Uses a source SOP (points, geometry, or a volume) to create falloff.

MOPs Plain Falloff - Generates a single falloff amount to apply evenly.

MOPs Remap Falloff - Remaps an existing falloff value using range and ramp controls.

MOPs Shape Falloff - Uses a primitive shape to generate falloff.

MOPs Spline Falloff - Uses a source spline to create falloff, similar to Object Falloff.

MOPs Spread Falloff - Generates an animatable "spreading" falloff effect from source points or attributes.

MOPs Texture Falloff - Remaps a projected texture map into falloff.

MOPs Transform Falloff - A transform handle that can be used to modify the transform of most other Falloff nodes.

MOPs Trigger Falloff (Plus) - Records when an existing attribute crosses a value threshold, then generates a falloff that can fade in or out after the trigger event.

Modifiers change transformations or other properties of MOPs packed primitives.

MOPs Aim - Aims packed primitives towards goal positions.

MOPs Align - Moves the pivots of packed primitives relative to their bounding boxes.

MOPs Clip by Attribute - Smoothly clips geometry at attribute thresholds. Useful for growing or eroding effects.

MOPs Color Modifier - Applies a color ramp based on falloff.

MOPs Curl Modifier - Applies curl noise to the position and/or orientation of objects.

MOPs Curve Toys (Plus) - Applies various deformations to polyline curves.

MOPs Deintersect (Plus) - Fixes overlaps between packed primitives, while optionally constraining position or orientation (or constraining to a surface geometry or SDF).

MOPs Delay - Applies a delay (time-shift) effect to various transform or timing properties of objects.

MOPs Edit (Plus) - Operates like a standard Edit SOP, but in local space for packed primitives (or points with an orient attribute). Can also duplicate geometry interactively.

MOPs Filter (Plus) - A temporal filter on point transforms or other attributes. Smooths out jittery movement or attribute changes.

MOPs Magnetize (Plus) - Pushes or pulls objects based on influence points.

MOPs Move Along Mesh - Pushes objects along a polygon surface.

MOPs Move Along Spline - Pushes objects along one or more splines (curves).

MOPs Noise Modifier - Applies several kinds of noise to the position and/or orientation of input objects.

MOPs Orient Mesh - Generates useful orientation frames on a polygon mesh for use with MOPs Move Along Mesh.

MOPs Pivot - AKA MOPs Align.

MOPs Randomize - Randomizes transforms and other properties of MOPs packed primitives.

MOPs Relax Modifier - Pushes objects apart to try to resolve overlaps.

MOPs Spring Modifier - Applies simple spring forces (Hooke's Law) to transforms of MOPs packed primitives.

MOPs Stepper (Plus) - Quantizes input transforms and attributes into discrete "steps".

MOPs Transform Modifier - Transforms MOPs packed primitives, similar to the Transform SOP.

These are miscellaneous tools, some of which are low-level nodes intended for use by TDs to create their own new MOPs operators.

MOPs Alembic Skeleton (Plus) - Creates a KineFX-compatible skeleton from an Alembic SOP.

MOPs Apply Attributes - The core API node of MOPs transformations. Applies template point attributes to packed primitives.

MOPs Attribute Mapper (Plus) - Allows you to create custom rules to quickly match simple attribute values to complex string attributes like texture paths or instance file paths.

MOPs Collision Geo (Plus) - Quickly and efficiently creates consistent collision geometry from lots of instances at once, including animated sequences.

MOPs Extract Attributes - Converts packed primitive intrinsics into template point attributes, usable by the Copy SOP.

MOPs Index From Attribute - Converts any point attribute (such as f@mops_falloff) into i@mops_index, suitable for use as the Template Points for a MOPs Instancer.

MOPs Neighbors - Computes an array attribute consisting of neighboring point numbers, and optionally connects them with polylines.

MOPs Noise Patterns - Create vector or scalar noise from a variety of noise functions.

MOPs Orient Curve - Creates an orientation frame for the points along a curve using MOPs Parallel Transport, with additional twisting controls.

MOPs Parallel Transport - Uses the Parallel Transport algorithm to generate normal, tangent and binormal vectors from an input spline.

MOPs Preview Falloff - Previews the f@mops_falloff attribute using colored sprites.

MOPs Reorient - Allows the local rotation axes of MOPs packed primitives to be changed without unpacking or changing the visible orientation.

MOPs Set Sequence Time - Changes the frame index of Packed Disk Sequences or Packed Alembics that were generated via the MOPs Instancer.

MOPs Visualize Frame - Visualizes the "up", "normal", and "side" axes of any points with an "orient" attribute.

MOPs Waveforms (Plus) - Generates or modifies attributes based on periodic waveforms.

MOPs DOPs (Plus)

See MOPsDOPs for information on the new dynamics nodes for MOPs+.