Exporting geometry to multiple meshes (FBX or Houdini Engine))

[pabloruiz55]

Hi! I've been scratching my head for days now about how to do this. Hope someone can help me.

I have a single geometry node and inside it I have a network that ends up generating like a boardwalk made of multiple connected primitives. See screenshot below.

If I either export to fbx or import the HDA into unity, what I get is a single object with a single mesh made of the whole path.

Instead, what I would like to get out of this is one object with one child object for each primitive that makes up the path.

Thanks!

[eikonoklastes]

Since you're in a Geometry network (SOPs), you're dealing with a single object, so it will export as a single object. 

There's probably a Python automation for this somewhere out there, but you need to basically follow these steps:

1. Use a File SOP, set to Write, inside a For Each Primitive loop to export each face out to a separate file.
2. Import all those files back into Houdini to create a separate Geometry network for each one (untick "Show sequences as one entry" in the import dialog and multi-select all the files as individuals entries).
3. When using the FBX Export dialog, select only those objects as the Source Objects.

That will give you a single FBX file with multiple, separate objects in them.

 

Edit: There seems to be a bug currently (in both 18.0.499 and 18.0.532), where specifying multiple objects to export in the FBX export dialog results in a broken export (the file reimports empty). Using Alembic works, however. I've submitted a bug report, if you're having the same issue, please do the same.

Edited July 26, 2020 by eikonoklastes
more info

[LaidlawFX]

Two alternate ways with Houdini Engine would be to make an object level subnet hda, then set up an geo node for each child and object merge each child sop piece into it.

The other hack way to do it in an hda is to use groups an on the Unity hda importer toggle on the split geometry based on groups.