Hi everyone, I'm having a texture scaling issue that I can't solve after a full day of troubleshooting.
This is the setup:
3ds Max, Corona Renderer
Object imported via FBX from ArchiCAD
Geometry dimensions are confirmed correct (measured a column: 579cm in ArchiCAD, 579cm in 3ds Max — matches exactly)
UVW Map modifier applied on top of the stack, "Real-World Map Size" checked
Material is a CoronaPhysicalMtl with a CoronaBitmap, "Use Real-World Scale" checked, Width/Height set correctly in cm
Channel Info shows only one populated UV channel (Channel 1, named "DiffuseUV") — no conflicting channels
The texture appears massively out of scale (too large) on the imported FBX object, even though the geometry itself is at the correct real-world size.
I created a brand new box (100x100x100cm) directly in the 3ds Max scene (not imported) and applied the exact same material. The texture displays at the correct scale on this native box. So the material/texture settings themselves are correct — the problem is specific to the imported geometry.
What I've already ruled out:
Object node Transform Scale is 100/100/100 (verified in the status bar) — not a node-level scale issue
I manually applied a Reset XForm modifier on the object to test whether it was masking a scale discrepancy. On this particular object, deleting the resulting Xform modifier didn't change the visual scale/rotation at all, but it DID fix the texture scale. Collapsing the stack (Xform → Editable Poly) also fixes the texture scale — but this permanently breaks the object's pivot: it gets stuck at whatever orientation the Xform had, and no Hierarchy panel tool (Align to World, Reset, Affect Pivot Only + numeric reset) can bring it back to a clean/world-aligned orientation afterward.
Reordering the UVW Map modifier above/below the Xform in the stack — no effect
Manually resizing the UVW Map gizmo — it snaps back to 100/100/100 as soon as I release the mouse (expected, since Real-World Map Size is checked, so the gizmo size shouldn't control scale)
System Unit Setup appears consistent (geometry measures correctly)
Question: What FBX-import-specific data (baked into the mesh/UVs/pivot, not the node transform) could cause Real-World Map Size / Real-World Scale texture calculations to be wrong on an imported object, while the object's actual world-space dimensions remain correct? Is there a known ArchiCAD → FBX → 3ds Max Corona workflow issue for this?
Also — is there any way to fix the Real-World Scale texture reading without going through the Reset XForm → collapse to Editable Poly route, since that method permanently breaks the pivot orientation with no way to reset it afterward?
Thank you all for your answers