Hello everyone, this is a question I have since I started working with houdini almost 3 years ago and yet I cant make it work.
How can I control the pivot transform of geometries I proceduraly generate and export as fbx in houdini?
What I am trying to do:
Inside a Geometry sop context, create an undefined number of geometries and make each one of them have a unique name and a pivot position of their own other than the origin when exported.
I already solved was how to control the hierarchy of the generated geometry, it can be done defining an attribute called "path" for each primitive. Is there any similar technique to define the pivot of the generated geometries in the hierarchy?
I export as fbx because my goal is to use them in game development and the pivot location can be used in an infinity of rendering optimization techniques for realtime.
I created a test scene here to showcase what I am trying to make.

As far as I understand, pivot is not a property of geometry. It is just an arbitrary point that you use for calculations when rotating. That is, it must be calculated at the final location according to your requirements. But if you want to calculate it in advance in Houdini, then in fact it is just a vector attribute for each point. All points of each cube must have the attribute "my pivot", which you will simply take when calculating rotations in the game engine.
That is, the task comes down to saving a custom attribute of a point in fbx and reading it in the game engine. I do not know if Houdini can save attributes in fbx, but I was not able to do this and transfer it to blender.
But if you use usd export, then the attributes are saved and read in blender. Perhaps the same is true for your game engine?
If someone explains why Houdini does not transfer attributes via fbx - that would be great.

You would have to pack them in some way. There is this with an example scene on the bottom: https://vij.app/fbx-hierarchy-pivots-export-from-houdini-to-unity/. [vij.app]
For individual objects its possible to set the pivot in the transform section of the obj node. But when you are scattering you will have to set up your own pivots and hierarchy. I think in this case using LOPs (instead of SOPs) would be a better way to go. When you assemble the scene in the Solaris you will get all that scenes have, you can write it to fbx or even better USD. SOPs are more like a single transform in the root.

Thank you!!!

This did not work with Unreal Engine, for some reason. Driving me nuts!