Revit to Ifc and Importing into Unreal via DataSmith : problem with materials

We got a Revit Model 2020 and we export our model with IFC 2x3 View default options.
In this model, we got a wall with a combined structure and each got a material.

When we open this IFC model exported into an IFC Viewer like BIMcollabZoom, we can find materials for this wall

When we import this IFC into Unreal 4.26 with DataSmith importer plugin : materials affected are bad!
Where is the problem?

Note that when I export from Revit With DataSmith plugin, imported materials for my wall are correct !
But I’d like to import an IFC not a DataSmith format…
Can anyone help me please?

Hi, is there anyone here who has already encountered this problem ? Thx

Hi Pierre,

This is a limitation of the IFC Engine DLL we use in our Datasmith IFC importer, which doesnt have the hooks to read more than one materials per mesh.

Any reason why you would use IFC instead of the Revit Datasmith plugin to bring your data in Unreal ?

Cheers !


Hi Antoine

To answer your last question, yes, there is a reason of importing an Ifc instead of a datasmith format exported by Revit or Archicad, or other. The reason is that most of the files we import into Unreal are in IFC format. Of course it works with a datasmith format, and Unreal correctly import all materials of my multiple layer wall.
Have a look in this capture : this is a wall with multiple layers and Datasmith plugin has correctly imported the materials :

But, in this exemple bellow, I’ve imported the ifc format with datasmith plugin and look : the imported wall got only one material furthemore the result is bad :

So, I’ve created a Python script to parse my IFC file to get correct informations and my script give met that information about my wall :

My problem is, how to modify the geometry of element to attribute the good materials into the wall imported by the datasmith plugin?
If I edit the StaticMeshActor, I do not know how to have a correct wall geometry like it was on a datasmith file format?
Does your ifc parser is not correct?
Whould my solution be to rewrite my own importer?
Thx Antoine. Hop you’ll undrestand my english… That’s funny because both we are french i think… :slight_smile:

Have a look here : when I import my ifc file format into Revit, he correctly import my wll with 4 layers and good materials of each layer of my wall.
Also with Archicad, th ifc wall is correctly imported…

Here in Archicad :

Hi, is there anyone here who has already encountered this problem ? Thx

Hi, is there anyone here who has already encountered this problem ? Thx

I am following a tutorial in Lynda about this (Revit/Max to Unreal (4.22) and the files that come from 3D Max using Datasimth don’t bring the materials associated with the files. … very frustrating