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[ABC] - attributes on transform in Maya -> Houdini


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Hello all,

I'm new to abc, and would like to get all the attributes I created in Maya to Houdini.

In fact I have created many attributes on transforms and shapes nodes and export them to abc ( all the attributes are correctly exported atm )

In Houdini, I can only see the "shapes attr" and not the "transforms attr" ( which seems logical for me as Maya and Houdini handle transforms differently )

Is there any trick to see this "transform attr" ?

I manage to get the value of these attributes with Python ( with the help of _alembic_hom_extensions ) , but I would like to see these attributes in the network view ( As I do with shapes attributes)

Any idea ?

Any help would be greatly rewarded with a big THX ! ;)

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Not that I know, but something tells me that arbitrary attributes don't transfer with Alembic.

I would transfer the attributes with image maps. First UV your object, then paint your attribute values from black to white. Then when you pipe it over to Houdini your can queery the maps in a shader or with a tex expression.

What is the effect you are trying to accomplish? Why not set the attributes in Houdini?

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  • 4 weeks later...

I think the following is similar to what you could do:

For attaching shape attributes to Alembic delayed load primitives, I made an attribcreate node with a _alembic_hom_extensions python expression used to access the attribute I want, using "abcPath" as the route to the correct shape in the abc file.

Could you not use the abcPath of the transform to get access to its attributes in the alembic file? I haven't checked personally.

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My solution applies to accessing a transform in a SOP, though... I suppose using the alembic archive node you would have to create a script to add all of the spare parameters to Houdini's object nodes with the right expression in each parameter.

Passing arbitrary attributes back and forth from Houdini to Maya is a little unsatisfying the way it works right now, but given how different the structure of each app is there probably isn't a much better way. I encountered the same attribute transferring issues when using a proprietary file format at a large post-production house.

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  • 1 month later...

Please check my old video about any data transfer between Maya and Houdini:

Idea is: you collect your attributes (including custom) in Maya and then transfer them as dictionary to your "receiver" operator in Houdini through rpc server (network).

Another way - same, collect data, save in text file (xml etc) and then in Houdini read this file (by Python based operator, for example) and apply data...

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