Order and names of surfaces in node and mesh files

[f.reichl]

Hi,

I'm wondering about the meaning of the "name" tag for ObjectMeshStatic elements in the node / world XML file, and wether what I'm experiencing is intended behavior or a bug. It seems that the order of surfaces in the node file needs to match the order of surfaces in the mesh file, otherwise assignments of materials / properties is not done correctly, is this intended? If so, what is the purpose of the "name" tag?

After some experiments, I find the behavior very inconsistent. I created a new world and added a mesh file with three uniquely named surfaces and assigned a unique material to each of them. For reference, I have three meshes in this order: Cylinder, Spiral, Sphere and three materials CylinderMat, SpiralMat, SphereMat.

Then I messed around with the surface order / naming in an XML editor and found the following:

• If the order is changed (exchange Spiral and Sphere), but the names are kept:
  • No errors / warnings in the log
  • Material assignments are switched - the materials are assigned "by index", ignoring the names of surfaces in the node file (Sphere now has SpiralMat and vice versa)
  • The editor shows the order of surfaces from the mesh file (Cylinder, Spiral, Sphere)
• If I rename Spiral to some random name:
  • An error message appears in the logfile: unused argument "material=07035bc1e402822c86b9179b215fe83ed2e47285" in "surface" node
  •  Spiral has now the SphereMat assigned
  • Sphere has mesh_base assigned
• The same happens if I exchange Spiral and Sphere and then rename Spiral to some random name

This seems very weird to me - I'd either expect the names to be ignored or correctly associated with the surfaces?

[morbid]

Hi,

XML files weren't designed to be manually edited. The XML structure in this case represents info from binary *.mesh file, almost any tag modification will break the required connections.

14 hours ago, f.reichl said:

what is the purpose of the "name" tag?

The only purpose is to represent this name in the Editor interface.

If you need a functionality for surface renaming it can be done with a custom tool. I think all required methods are listed in the Mesh Class. We thought of a feature that will allow surfaces renaming right in the Editor, but it will break major FBX pipeline: if you'll rename a surface your data will be wiped after FBX reimport.

Thanks.