What's the deal with exporting alembic files and instances from Bifrost Graph?

[PuChiNgBaLLz]

Hello there, my first attempt to cache an animation to .abc

I tried to export the files as the graphs look like and it creates 1KB file for each frame.

These are 2 graphs I tried

bfgraph.png

In the 1st case, the File_Cache node is connected directly to the randomize, if I set the bake instances in between then it properly generates the .abc files of about 1.8 MB each, and they can be read normally if the file cache node changes to Read Mode or Lazy.

bfgraph2.png

In the 2nd case, is the same, a bunch of 1 KB files are created even the node is connected following it's own description to work.

Usage

1. Set a file path for the cache of your simulation in filename. It may contain environment variables, such as $HOME for your home directory.
2. Plug the output of a simulation into objects and use out_objects as the output, or first_object to avoid conversion to an array.
3. Go to the start frame of the simulation.
4. Set mode to lazy mode.

In this case I tried using every File cache outputs in the Output node, but nothing worked. Setting the file cache to .bob in any of the graphs works just fine in write/lazy mode.

So these are my questions:

1 - WHY doesn't it recognizes a simulation result as something to write, if it's in the node description?

2 - Does it saves instances or they must be baked/merged to a single object?

I find the explanation in the Bifrost site too brief, same for write alembic node.

[sepu6 · Accepted solution]

The alembic file in BF does not support instances. So as you said if you need to save as an .abc then you gotta bake them. 

You can save pts from a simulation so for example you could save as an alembic the particle solver, MPM, FLIP