My alembic scene has multiple shapes. I want to import it to Houdini as a single node. This is possible by switching off the load hierarchy option when import, or by putting Alembic node in Geometry node and setting filePath of Alembic node to the scene path. But then I need to transform each shape differently. How is it possible?

Thanks.

In short, I need to import all shapes in the alembic scene as a single node in Houdini but then transform each shape differently.

Yes use a single object with a single Alembic SOP to load in the Alembic hierarchy off of disk. One short-cut to doing this is to use the menu option File > Import > Geometry and locate your .abc file and load it in. This creates an object with an Alembic SOP. I rarely if ever use the File > Import > Alembic Scene.

I don't know what types of transforms you wish to apply to the various Alembic primitives but they are indeed single point primitives in Houdini. Many SOPs work with Alembic and Packed primitive types such as the Transform SOP which modifies the intrinsic transforms of the Alembic primitives.

Transform SOP has the Group field to isolate to one or more Alembic primitives. One thing you can do on the Alembic SOP is to set the Primitive Groups parameter chooser to one of the many options to create groups for the primitives. Transform SOP can now work with groups directly.

The Edit SOP in Primitive or point selection can also transform Alembic primitives directly in the viewport as you can with the Transform SOP.

What type of transforms do you wish to apply to the Alembic Primitives?

Thanks Jeff. I haven't tried this since Houdini won't open in my laptop at home (The error message has been attached here. Any idea?)

The idea is: The imported alembic scene will be an asset (created in maya), mostly a prop or environment (NOT a character). In the shot, this prop will be translated/rotated in maya by animation team later. Now, I need to apply this animation info from maya (which was saved in some format) into the prop's alembic scene opened in Houdini. I know it's simple if the hierarchy is there in the imported alembic scene in Houdini but I hate the full hierarchy! :-) So I have the prop as a single node in Houdini. The problem is the prop might have multiple shapes.

Hi Jeff,

I used Alembic node to load abc file, then connected it to Transform node. Then played with Primitive Groups, Creat Primitives for, Group, Group Type, etc of both nodes, alongwith modifying Translate values of Transform SOP. But no changes seen in the viewport. Happened the same with Edit SOP also.

Can you attach the simplest .hip file by doing this with single abc file with multiple shapes? I have limitations to share mine here since I am working at office.

Thanks.

Houdini version is 15.0.271

Oh… It was related to adjusting Display/Render flags of Transform SOPs.

Another issue:
I have multiple Transform SOPs now, each using a specific shape in the Alembic SOP. If I set the Display/Render flags on one, I see it disables it on the others and so only the transform of that particular Transform SOP is considered by neglecting the others' transforms in the display and render. How can we keep the transforms of all Transform SOPs together (since each SOP is used for each primitive's/shape's transform) ?

Solved this in a way by connecting Edit SOPs one after another, each using each shape as Group. Then enabled Display/Render for the last one. But is there a better way to reduce the node count in the Tree View?