From db5fff6cccb3ce2fb02a9614369e620bae75c3d3 Mon Sep 17 00:00:00 2001
From: Roy-043 <70520633+Roy-043@users.noreply.github.com>
Date: Sat, 24 Jan 2026 20:43:42 +0100
Subject: [PATCH] BIM: fix BuildingPart issues with Arch_Reference

---
 src/Mod/BIM/ArchReference.py | 34 +++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/src/Mod/BIM/ArchReference.py b/src/Mod/BIM/ArchReference.py
index 3568bd0620..1bb19b7195 100644
--- a/src/Mod/BIM/ArchReference.py
+++ b/src/Mod/BIM/ArchReference.py
@@ -171,6 +171,10 @@ class ArchReference:
                                     FreeCAD.Console.PrintError(t + "\n")
                         else:
                             for part in self.parts.values():
+                                if part[3]:
+                                    # Do not include BuildingParts as their
+                                    # shape is just a copy of their group:
+                                    continue
                                 f = zdoc.open(part[1])
                                 shapedata = f.read()
                                 f.close()
@@ -385,6 +389,7 @@ class ArchReference:
             label = None
             part = None
             materials = {}
+            is_buildingpart = False
             writemode = False
             for line in docf:
                 line = line.decode("utf8")
@@ -392,6 +397,8 @@ class ArchReference:
                     n = re.findall(r"name=\"(.*?)\"", line)
                     if n:
                         name = n[0]
+                elif 'class="BuildingPart"' in line:
+                    is_buildingpart = True
                 elif '<Property name="Label"' in line:
                     writemode = True
                 elif writemode and "<String value=" in line:
@@ -417,11 +424,12 @@ class ArchReference:
                     writemode = False
                 elif "</Object>" in line:
                     if name and label and part:
-                        parts[name] = [label, part, materials]
+                        parts[name] = [label, part, materials, is_buildingpart]
                     name = None
                     label = None
                     part = None
                     materials = {}
+                    is_buildingpart = False
                     writemode = False
         return parts
 
@@ -452,7 +460,11 @@ class ArchReference:
             return []
 
         totalcolors = []
-        parts = [obj.Part] if obj.Part else self.parts.keys()
+        if obj.Part:
+            parts = [obj.Part]
+        else:
+            # Do not include BuildingParts as their shape is just a copy of their group:
+            parts = [key for key, val in self.parts.items() if not val[3]]
         lenparts = len(parts)
         for i, part in enumerate(parts):
             lenfaces = len(self.shapes[i].Faces)
@@ -471,7 +483,6 @@ class ArchReference:
         zdoc = zipfile.ZipFile(filename)
         if not "GuiDocument.xml" in zdoc.namelist():
             return []
-        colors = []
         colorfile = None
         with zdoc.open("GuiDocument.xml") as docf:
             writemode1 = False
@@ -481,26 +492,27 @@ class ArchReference:
                 line = line.decode("utf8")
                 if ('<ViewProvider name="' + part + '"') in line:
                     writemode1 = True
+                elif writemode1 and '<ViewProvider name="' in line:
+                    # We have reached the next item:
+                    break
                 elif writemode1 and ('<Property name="DiffuseColor"' in line):
-                    writemode1 = False
                     writemode2 = True
                 elif writemode1 and ('<Property name="ShapeAppearance"' in line):
-                    writemode1 = False
                     writemode3 = True
                 elif writemode2 and ("<ColorList file=" in line):
                     n = re.findall(r"file=\"(.*?)\"", line)
-                    if n:
+                    if n and n[0] and n[0] in zdoc.namelist():
                         colorfile = n[0]
+                        writemode3 = False
                         break
                 elif writemode3 and ("<MaterialList file=" in line):
                     n = re.findall(r"file=\"(.*?)\"", line)
-                    if n:
+                    if n and n[0] and n[0] in zdoc.namelist():
                         colorfile = n[0]
+                        writemode2 = False
                         break
 
-        if not colorfile:
-            return []
-        if not colorfile in zdoc.namelist():
+        if colorfile is None:
             return []
 
         cf = zdoc.open(colorfile)
@@ -526,7 +538,7 @@ class ArchReference:
                 for material in colors:
                     material.Transparency = 1.0 - material.Transparency
 
-        if writemode3:
+        elif writemode3:
             # File format ShapeAppearance files in FCStd file:
             # - 1st byte: number of faces
             # - Next 3 bytes: zero