It imports in with a blank texture. It imports as if I didn't run the script at all.
The structure looks like this before max changes it when max exports it.
I am a bit confused by what you are doing, opening the model you shared- it is empty - seems there is a missing reference in it :
Missing this : @assets/Game/CoD/xmodels/berlin_com_office_chair_black.usdc@@
So this seems like a complex asset....
When you import it in max, what exactly are you importing? The scene? one chair? Or are you referencing it in as a USD Stage object? And when you export are you re-exporting the whole thing? Import/export is definitely lossy - but it is similarly lossy in maya, in maya what are you doing exactly? Importing the whole scene? a subset? Loading a USD stage?
If you can provide a small subset of the scene that has a full repro case, and detailed steps (import of what, export of what, to what, etc.) it will help.
Many things come into play, where are the material bindings authored from unreal? on what USD layer? If i can see how the materials are setup, what you import in 3dsMax, and then what layer you overwrite (i assume?) on export, it should be easier to tell.
If you import the entire scene in 3dsMax and re-export to a single layer, that will be an entirely new thing, definitely.
I'm only trying to export a single model. File > export selected. I'm simply doing the same export and import process for both. I select the individual model, export it individually as usdc and I import it into max. Hopefully the model I'm exporting here of a billboard can demonstrate the hierarchy in the USD explorer-which completely changes once I export it from max whether I make changes to it or not. So take the file I'm giving you. If you open it in Unreal Engine in the USD explorer it will show up with all its native Unreal materials intact. Take the file I uploaded and export it from max and see what happens to its paths.
Notice the USD layout in my first image. If I open this in Unreal as it is the Unreal materials and everything will be laid out as they belong.
and here is what happens to it after max. This I believe is the problem. Max is destroying the structure I established. Even if I don't do anything to the usd, if I simply export it from max the hierarchy is ruined and Unreal no longer recognizes it since the paths are messed up.
The other applications aren't doing this to my USDs. They export with their original USD hierarchies intact.
That model in the zip is also empty. Likely referencing another layer which is not in the zip.
When you import, the usd content is converted to 3dsmax, there is no longer any USD involved, when you reexport there is no guaranty of preserving the initial hierarchy - the rules of max and usd are not the same, conversion can be lossy, especially on schemas max nothing about, like unreal shaders. If the material binding set in unreal was a collection based binding, and the material lived elsewhere, you wouldn't have this problem. We dont export materials inside geometry to ease reuse.
What exactly are you doing in maya/blender? maya import + export is definitely lossy as well, and i just tried in blender (latest public downloaded just now) and it does not preserve the hierarchy either on import + export :
I am not sure you are actually import/exporting (in the same sense as the max import/export - i.e. "import" means something different in unreal vs 3dsmax) anything to/from unreal, just loading/saving a layer - which itself carries nothing, elsewhere, given your zips are void of any geometry. I.e. I guess it's not converting to unreal data and converting back to USD.
This is what your unreal "export" looks like :
#usda 1.0
(
defaultPrim = "Root"
metersPerUnit = 0.009999999776482582
upAxis = "Z"
)
def Xform "Root" (
assetInfo = {
asset identifier = @../../../../../../Users/proto/Desktop/billboard.usdc@
string name = "Untitled_1"
dictionary unreal = {
string assetType = "World"
string contentPath = "/Temp/Untitled_1.Untitled_1"
string engineVersion = "5.4.4-35576357+++UE5+Release-5.4"
string exportTime = "2024.09.12-20.30.07"
}
string version = "F1D847C14E4DEDBC97DBE2E0B2B9D186392581DC"
}
)
{
def Mesh "SM_Billboard_SIde_Long_03" (
prepend references = /Game/Cyberpunk/Meshes/Props/BillBoard/SM_Billboard_SIde_Long_03.usdc@
)
{
token visibility = "inherited"
matrix4d xformOp:transform = ( (1, -0, 0, 0), (0, 1, -0, 0), (0, 0, 1, 0), (620, 550, 0, 1) )
uniform token[] xformOpOrder = ["xformOp:transform"]
}
}
You can see it doesnt itself carry anything, only a reference to `prepend references = @assets/Game/Cyberpunk/Meshes/Props/BillBoard/SM_Billboard_SIde_Long_03.usdc@`
Something can definitely be done with some scripting, or by structuring the assets and where the bindings are done differently - if the material is not "under" the prim you need to import, and the binding is done on a different/stronger layer than where the mesh lives, you should be able to then import/export the mesh layer, a preserve the material in the scene that references that mesh.
With a working scene sample it would be easier to see what the "no scripting" options are - if any.
