I should clarify here what you are looking for if you do intend to open up the
Assuming you mean an image texture, you are looking for is
IfcSurfaceStyleWithTextures, which would then assign an
IfcImageTexture with a URI to your image file. Assuming those are there, then it is a relatively safe assumption that somewhere in the IFC file, your texture is captured. You then need to verify that the texture is assigned as a style representation for your
IfcMaterial which is associated with your BIM element / shape. This differs between IFC2X3 and IFC4, and so you will need to check the specification to know exactly what the process is. For instance, I am aware that in Revit exporting an IFC4, it incorrectly assigns presentation styles using deprecated methods, which may explain why things don’t work (specifically, Revit incorrectly uses
IfcPresentationStyleAssignment on export).
If you share your file here (by exporting a portion of your model, if you are concerned about intellectual property), we can help more.