If I press File > Import into Level… and then pick a USD that has a model that contains 2 materials in a child scope, and has 1 of those materials assigned to its mesh, the textures and parameters of the material are correct, but the name of the material is ALWAYS the first material from the scope.
EXAMPLE USD, NOT IMPORTABLE:
#usda 1.0
(
customLayerData = {
string ExportType = “Map”
string NameOverride = “Canyon”
}
defaultPrim = “Canyon”
metersPerUnit = 1
)
def Xform “Canyon” (
kind = “assembly”
)
{
def Scope “Area2”
{
def Xform “CNYN_Bar_Floor_01_006” (
kind = “model”
)
{
def Scope "Look"
{
def Material "CNYN_Bar_Floor"
{
}
def Material "CNYN_Motel_TileFloor"
{
}
}
def Mesh "pCube7"
{
rel material:binding = </Canyon/Area2/CNYN_Bar_Floor_01_006/Look/CNYN_Bar_Floor>
custom string materialName = "Floor"
}
}
}
}
In the example above, the unreal material instance constant is named MI_CNYN_Bar_Floor
However, if I modify the usd file by hand and simply switch the order of the Material’s in the Scope “Look” to be this instead:
def Scope "Look"
{
def Material "CNYN_Motel_TileFloor"
{
}
def Material "CNYN_Bar_Floor"
{
}
}
Then when I do File > Import Into Level… on that new usd file, the material’s parameters are exactly the same as before, but the name of the material is “MI_CNYN_Motel_TileFloor”
This makes it really tough to do post processing on the scene after importing it.