| On this page |
Unresolved
These functions are not part of “HOM proper”. They are not under the hou package and are not integrated into the object model. Future versions of Houdini may have better integrated support for working with Alembic data in Python.
To use the functions in this module, launch hython and import _alembic_hom_extensions.
>>> import _alembic_hom_extensions as abc >>> print abc.alembicGetSceneHierarchy("panda.abc", "/") ('ABC', 'unknown', (('Geo', 'cxform', ...
Tips ¶
-
Importing this module does not use a Houdini license.
-
While the functions work with file paths, they don’t open and close the files every time a function is called. The code keeps an internal cache of open Alembic files to make repeated calls on the same file efficient.
-
The tuple of 16 floats returned by
getLocalXformandgetWorldXformcan be directly passed to the hou.Matrix4 constructor to create a hou.Matrix4 representation of the transform.
Common arguments ¶
abcPath
A file path to the Alembic file.
objectPath
The path within the alembic file to the object.
name
The name of the attribute to read.
sampleTime
The animation time at which to compute the value. This is a fractional value in seconds. If you have a frame number you must divide by the frames-per-second before passing it to the function.
Functions ¶
alembicArbGeometry(abcPath, objectPath, name, sampleTime)
→ (value, isConstant, scope)
Gets the value of an object attribute. Returns None or a tuple of the value of the attribute; a boolean indicating whether the attribute is constant over time; and a string indicating the scope of the attribute: varying, vertex, facevarying, uniform, constant, or unknown.
alembicBoundingBox(abcPath, objectPath, sampleTime)
→ (value, isConstant)
Gets the bounding box of an object. Returns None or a tuple of a bbox tuple and a boolean:
-
The bounding box as a tuple of 6 floats.
-
The bounding box is an optional property of the Xform and the Root node. If it doesn’t exist on the given object path, the retval will be None.
-
The second item is
Trueif the bounding box is constant over time.
alembicClearArchiveCache()
Clears the internal cache of open Alembic files.
alembicGetArchiveMaxCacheSize()
→ int
Returns the maximum number of Alembic files to keep open in the cache. You can set this limit using alembicSetArchiveMaxCacheSize.
alembicGetCameraDict(abcPath, objectPath, sampleTime)
→ dict
Returns a dictionary of camera parameters for the given object.
alembicGetObjectPathListForMenu(abcPath, objectPath, sampleTime)
→ tuple
Returns a tuple of strings in the form expected for menu callbacks, where each object is represented as a token/label pair.
alembicGetSceneHierarchy(abcPath, objectPath)
→ (object_name, object_type, children)
Returns a hierarchy of tuples, where each tuple is in the form
item = ("object_name", "object_type", (item, ...))
The object_type may be one of:
cxform
A constant transform node.
xform
An animated transform node.
camera
A camera node.
polymesh
A polygonal mesh shape node.
subdmesh
A subdivision surface shape node.
faceset
A face set shape node.
curves
A curves shape node.
points
A points shape node.
nupatch
A NuPatch shape node.
unknown
An unknown node type.
alembicSetArchiveMaxCacheSize(number_of_files)
Sets the maximum number of files to keep open in the cache.
abc.alembicTimeRange(abcPath)
Returns the time range of the given Alembic file.
alembicUserProperty(abcPath, objectPath, name, sampleTime)
→ (value, isConstant)
Gets the value of a user property. Returns None or a tuple of the value of the attribute and a boolean indicating whether the attribute is constant over time.
alembicUserPropertyMetadata(abcPath, objectPath, sampleTime)
→ value
Returns None or a JSON dictionary containing a map of user property names –> user property metadata.
alembicUserPropertyValues(abcPath, objectPath, sampleTime)
→ value
Returns None or a JSON dictionary containing a map of user property names –> user property values.
alembicUserPropertyValuesAndMetadata(abcPath, objectPath, sampleTime)
→ (values, metadata)
Returns a tuple of JSON ditionaries. The first contains a map of user property names to user property values, the second a dictionary of user property names to user property metadata which is used to interpret the first dictionary.
alembicVisibility(abcPath, objectPath, sampleTime, check_ancestor=False)
→ (value, isConstant)
Gets the visibility of an object. Returns None or a tuple of an integer and a boolean:
-
The first item is
0for hidden,1for visible, or-1for “use the parent object’s visibility”. -
The second item is
Trueif the visibility is constant over time.
If you pass check_ancestor=True, the function will check the visibility of ancestor objects to return a known value (0 or 1) instead of -1 as the first item.
getLocalXform(abcPath, objectPath, sampleTime)
→ (xform, isConstant, inherits)
Gets the local transform of an object. Returns a tuple of:
-
The transform as a tuple of 16 floats.
-
A boolean indicating whether the attribute is constant over time.
-
A boolean indicating whether the object inherits its transform from its parent. If this is
False, the object is disconnected from the transform hierarchy.
getWorldXform(abcPath, objectPath, sampleTime)
→ (xform, isConstant, inherits)
Gets the world transform of an object. Returns a tuple of:
-
The transform as a tuple of 16 floats.
-
A boolean indicating whether the attribute is constant over time.
-
A boolean indicating whether the object inherits its transform from its parent. If this is
False, the object is disconnected from the transform hierarchy.