AlembicArnoldProcedural usage:

-filename /path/to/some/archive.abc

This is the only required argument. It has no default value.

-frame 42

The frame number to load from within the archive. The default value is 0. This is combined with -fps to map to Alembic time units (double-precision seconds).

-fps 24

Combined with -frame above. The default value is 24

-shutteropen 0.0
-shutterclose 0.5

These are frame-relative values which specify the shutter window. The procedural will include all samples present in the archive which are relevant to the shutter window. The default value of both is 0.0 (no motion blur).

-objectpath /assetroot/characters

If specified, only objects at or below the provided path (within the archive) will be emitted. When combined with -excludexform, this can also be used to load individual leaf locations within an externally defined hierarchy. Be aware that in that case, you'd need to set the "matrix" and "inherit_xform" parameters on the procedural node itself. If the path points to a single "faceset" object directly beneath a polymesh or subdivision mesh, it'll add a "face_visibility" user data array.


-excludexform

If specified, the "matrix" parameter will not be set on the resulting primitive nodes.

-subditerations 2

For AbcGeom::ISubD objects, this option specifies the "subdiv_iterations" value. It currently has no effect for other primitive types. The default value is 0.

-nameprefix some_prefix__

Because node names are unique scene-wide in arnold, this allows you control potential name clashes when loading or instancing an archive (or multiple equivalently named archives) multiple times. The default name of each node is its full path within the alembic archive.

-makeinstance

This behavior is disabled by default. If enabled, the procedural will attempt to identify identical primitives (using Alembic's per-array-property hash keys) and create corresponding "ginstance" nodes. Two primitives are considered equivalent if the keys of their relevant point position samples match along with any specified subdivision values. This works across multiple archives or invokations of the procedural. It currently does not write unique user data per instance but will likely do so automatically (when necessary) in a future release. The ray visibility of the source primitive will be set to AI_RAY_NONE and the "ginstance" node's will be set to that of the calling "procedural" node.


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User Properties

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There are key user attributes that can be added to the procedural that affect the contense of the generated geometry:

The procedural will detect various custom user attributes as json dictionaries. where ever a target node is given it can be given as a alembic object path ("/root/path/to/object"), a wildcard regualr expression ("*match*"), or a key of an exported geometry constant "tag" attribute with key:value pairs.

 * overrides <string>
 * overridesfile <string>

 This is either a JSON dictionary containgin key, dictionary pairs :

 {"target":{"attr":value}} 

 or  a path to a file containig key:dictionary pairs with in a larger dictionary key named "overrides". 

 {"overrides":{"target":{"attr":value}}}

 These attriubtes need to match the available attreributes for the tyope of geometry that you are overiddeing. To find the aproppriate attributes use kicjs info tools e.g. kick -info polymesh will give the attributes available on a polymesh. In addition to these attributes you can also use a "matte" boolean attribute and set it to true and the procedural will add a usr attribute called "enable_matte" to the target object(s) 

 * userAttributes <string>
 * userAttributesfile <string>

 These attributes are simaler to the opverrides, however they only add user attributes, usefull for linking to procedural shader operations and using for userdata operations.


 {"userAttributes":{"target":{"attr":value}}}

 * shaderAssignation <string>
 * displacementAssignation <string>
 * shaderAssignationfile <string>

 Shader and displacement assignment is done from a shader:list pattern, so you can choose a shader and assign it to multiple objects within the heirarchy:

 {"shaderName":["/path/to/object","*match*","tag"]}

 they can also be assigned using a JSON file under the two keys "shaders" and "displacement"

 * assShaders <string>

 Thisn is the optional path to a ass file containig shaders that you wish to load in to arnold, these shaders may be ones you a referenceing to in the shaders attribute above.


STILL TO DO:
-AbcGeom::ICurves
-AbcGeom::INuPatch
-AbcGeom::ICamera