derrick

derrick

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Getting alembic frame range as an attribute July 14, 2022, 9:26 a.m.

The Alembic HOM Extensions provide access to the range of time samples in the Alembic archive. You can convert these to frame values if needed.

import _alembic_hom_extensions as ahe
start_time, end_time = ahe.alembicTimeRange(filename)

Exporting alembic with instances is bigger file size?! June 2, 2022, 11:47 a.m.

midorisalt
I have attached a test scene with showing the problem. There are two alembic outputs inside the geo node, and the only difference is that the copy to points node has "Pack and Instance" enabled in the right side tree.

Instancing is not being used in your example as the Alembic ROP is set to export deforming geometry. You can easily check if instancing is used with Packed Alembic primitives by inspecting the "abcsourcepath" intrinsic.

The structure of Alembic archives is significant. It is good practice to explicitly specify where you want everything to be placed in an Alembic archive. Attached is an updated example that uses instancing and structures the scene so each box has a separate Alembic transform node associated with it.

Alembic archives have a lot of overhead when using instancing. For such small objects like a box, the overhead will significantly outweigh any possible benefit.

Alembic camera motion blur issue with Renderman Feb. 9, 2021, 3:34 p.m.

Can you share an example Alembic archive and .hip file illustrating the problem? We have not been able to reproduce the described behaviour.