Reimport problem with new objects.


I use 3ds max Datasmith exporter.
I have my scene already imported into UE.
At this point everything works alright.

But I’ve made changes to only some part of my original max scene. Some objects have been added.
Since scene is big I use “Export Selected” option. I override previously made *.udatasmith file.

Now there is a problem.

I use “Reimport” option on Datasmith Scene Asset.
If Sync Current Level Actors -> Datasmith Scene Actors is:

A. checked: most of my scene disappears since “export selected” option was used while exporting, and *.udatasmith file contains description only for those selected objects.
B. unchecked: my scene stays intact, objects are updated accordingly to newly exported version, but objects which were not present in scene before ARE NOT added to the scene (are imported to the content browser though)

Is there any way to use Export Selected, update already imported content AND automatically add new objects to the scene?

The way Datasmith works is that it tracks the content of a datasmith file by looking at unique IDS generated by 3ds max. When you overwrite an existing datasmith scene by exporting only selected object, what happens is that Unreal importer think s that those objects were deleted.

You should always export a consistent set of objects to a datasmith file.

How long does it take to export and reimport everything in your case?

Yup, that exactly the case. Would be perfect if exporter could “update” the udatasmith file and asset folder, adding new objects and updating existing ones.

Whole export and reimport takes like 5 minutes. Not long, but I have to do it quite often in early stages of project.

Some users are breaking it down by layers where one datasmith file is created (furniture, building, landscape) which helps splitting the work.

That’s a good idea. Thanks!

Since udatasmith file is a json formatted I think I could try writing proof of concept merger. This could substitute for “update” functionality for exporter.