Help with Forest and Unreal

[Arphalax]

Not sure if this is the correct forum, but I’m hoping someone has run into this before.

I’m following the official iTooSoft tutorial for exporting ForestPack to Unreal using Datasmith, specifically the “Replace References” method:
https://www.itoosoft.com/tutorials/how-to-export-forest-pack-to-unreal

The initial export works perfectly, the bounding boxes get replaced with the correct plant meshes, materials look good, performance is fine, etc.

The problem appears when I need to make changes in 3ds Max (which is very common in production):

• adjusting Forest density / distribution
• moving or deleting individual instances
• small layout tweaks requested by the client

When I re-export and reimport the Datasmith scene in Unreal, Datasmith:

• replaces all the plants back to the original bounding boxes
• removes all the Static Mesh references that were manually replaced

This means that for every small Forest change, I have to:

• re-replace ~30 different plant references again
• redo all the assignments manually

which is extremely time-consuming and error-prone.
I’ve tried many combinations of Datasmith reimport options but I haven’t been able to prevent this behavior.

What I’m trying to achieve:

• Reimport only transform / instance data from ForestPack
• Keep the already-replaced Static Mesh assets in Unreal
• Avoid resetting everything back to bounding boxes

My questions:

• Is there a way to reimport ForestPack via Datasmith while preserving replaced Static Mesh references?
• Is this workflow fundamentally not supported?
• Am I missing a specific Datasmith or ForestPack setting?
• Is there a better production-safe workflow for iterative Forest updates?

Any insight, alternative workflows, or confirmation that this is a known limitation would be greatly appreciated.

Unreal 5.6
Max 2024
Forestpack 8.2.2

Thanks!

[Michal Karmazín]

Hi,

First, it’s worth mentioning that we don’t have much control over how Datasmith exports our plugins, as Epic uses our APIs to support ForestPack and RailClone, not the other way around. That said, we’ll see if there’s any way we can help, but unfortunately, due to our current workload and other pending tasks, I’m unable to provide a specific timeframe. Most likely, we’ll be able to explore possible solutions in the new year. Thank you for your understanding.

Best regadrs,

[Arphalax]

Thanks, any useful information will be very welcome. Happy holidays.