Build or update hierarchy
Click to read the archive file in File name and build a hierarchy of Houdini objects from the objects in the archive.
Build Hierarchy Using Subnetworks
The Alembic Archive will import the alembic objects either using subnetworks (i.e. children contained in a subnet), or by wiring the nodes in a hierarchy (i.e. a single network).
Build Hierarchy With Channel References
When building Houdini objects, create channel references to the root Alembic archive. This means that any changes you make to the Alembic Archive’s parameters will be picked up automatically by children. However, there will be potentially thousands of channel evaluations.
With no channel references, you can propagate parameter changes on the Alembic archive to the child objects using Push Parameters To Children.
Load Hierarchy As One Single Geometry
Instead of creating Houdini objects for each Alembic transform and shape, this will load the Alembic archive into a single geometry node.
This will still create Houdini objects for Alembic cameras.
Flatten Visibility Evaluation
In Houdini, when a subnetwork’s display is turned off, all its children will also not be displayed. Alembic allows children of a network to be displayed, even when the parent is not displayed.
Flattening visibility forces each object to determine its own visibility rather than relying on parents. This is slightly more costly, but will reproduce Alembic’s visibility model.
Push Parameters to Children
Propagate changes to parameters to the child objects (see Build Hierarchy With Channel References).
Clear the Alembic cache and reload fresh geometry for all the shapes without rebuilding or updating the archive hierarchy.
Compared to Build or Update Hierarchy, this is the faster way to update an Alembic archive version when there is no hierarchy change.
Path to the Alembic archive (
A path to one or more objects inside the archive. If specified, the node will load only these object and their children. The default is blank, which means load all the geometry in the archive.
The Alembic frame at which to sample the geometry. The default value is
$F (Houdini’s current frame). If you need to offset the start time of the
animation in the archive, you can add or subtract frames (e.g.
$F + 48).
Frames per second
Combined with the Frame parameter, this is used to convert Alembic’s
time-based animation to Houdini frames. The default is
current frames-per-second setting). If the archive file was created with a
different FPS, you will need to enter it here.
How to load the Alembic geometry into Houdini:
Alembic Delayed Load Primitives
These custom primitives are very light-weight and will display faster in the viewport. They are not as full featured as other Houdini primitive types (i.e. ray-tracing is not very accurate), but can be converted to other primitive types if need be.
Unpack Alembic Delayed Load Primitives
Load the geometry as Alembic packed primitives and then automatically unpack the geometry to create native Houdini geometry.
Load Houdini Geometry
Convert the Alembic primitives to use native Houdini geometry.
Houdini Point Cloud
P attribute from the Alembic primitives as a Houdini
point cloud. Currently, this doesn’t load any attributes other
Load only the bounding boxes of the Alembic primitives.
How the Alembic geometry is displayed in the viewport.
The Alembic geometry is fully displayed.
Only the points are displayed.
Only the geometry bounding boxes are displayed.
Only the geometry centroid is displayed.
No geometry is displayed.
How Alembic user properties should be handled.
Do Not Load
User properties are not loaded.
Load Values Only
User property values are loaded as a JSON dictionary into a primitive string attribute.
Load Values and Metadata
User property values are loaded as a JSON dictionary into a primitive string attribute. User property metadata, useful for interpreting and processing the values, is loaded as a JSON dictionary into a separate primitive string attribute.
Use this multiparm to rename Alembic point, vertex, and/or primitive
attributes to their Houdini equivalents and optionally change their type
info. For example, remapping
Cd (diffuse color). Click
the + button to add a new mapping.