alembic layering in houdini 17.5

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in houdini 17.5 there seems to be alembic version 1.79 which should include alembic layering. I cant find any information about this in the docs. there is a layer parm which just seems to add another alembic to the alembic node. I would like to be able to take specific attributes as point reference or uv from another alembic. Any knowledge about this?

Regards Alexis
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leoYfver
there is a layer parm which just seems to add another alembic to the alembic node.

That is how Alembic layers are used – you only specify a list of files. All of the details around what a layer does is specified when you author the layer.

leoYfver
I would like to be able to take specific attributes as point reference or uv from another alembic.

Alembic layers can be authored with the Alembic ROP. Authoring an Alembic layer is very similar to exporting a regular Alembic archive but you specify a subset of the data you want in your layer and how that data should be used when the layer is applied (see the parameters in the Alembic ROP's “Layering” tab). Attached is a simple example.

Attachments:
alembic-layer-example.hip (123.0 KB)

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Thanks for file!

I was kinda hoping i could merge 2 alembics with same path hierarchy without having to do anything from the rop. Just link the layerfile in the alembic node and choose what to override/merge or prune.
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I was kinda hoping i could merge 2 alembics with same path hierarchy without having to do anything from the rop. Just link the layerfile in the alembic node and choose what to override/merge or prune.

The design is actually dictated by the Alembic library itself. All software that can read Alembic archives can support layers by allowing users to specify a list of files – there are no other inputs or configuration options. The authoring of Alembic layers is where all of the decisions are made.
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We usually use alembics from other softwares so we dont have access always to the alembic rops layering. I was thinking more of the workflow in these examples below. Sorry if im misunderstanding but thanks for the help and I will try to use the workflow provided.

https://www.clarissewiki.com/4.0/alembic-layering.html [www.clarissewiki.com]

https://vimeo.com/250556533 [vimeo.com]
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That software appears to operate the same way: It looks like they are generating a static base, a deformation layer (that only hold new point positions and normals), and a texture layer (only containing texture coordinates). You also import the scene with the layers applied by simply providing a list of file paths.

Attached is a similar example. You don't need access to the original Alembic exporter to create a layer. In this example, we import an Alembic archive and build new layers for it.

Attachments:
alembic-layer-example-2.hip (154.1 KB)

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