improved relative path handling for textures #3365

now we're going to store all texture paths in .ifc as posix to keep them working if .ifc moved from one platform to another

previously it was saving all paths as absolute

src/blenderbim/blenderbim/tool/blender.py

@@ -215,6 +215,21 @@ class Blender:
             return current_iteration
         return cls.ensure_unique_name(name, objects, iteration + 1)
 
+    @classmethod
+    def blender_path_to_posix(cls, blender_path):
+        """Process blender path to be saved as posix.
+
+        If path is relative the method will keep it relative to .ifc file
+        """
+        if blender_path.startswith("//"):  # detect relative blender path
+            ifc_path = Path(tool.Ifc.get_path())
+            abs_path = Path(bpy.path.abspath(blender_path))
+            path = abs_path.relative_to(ifc_path.parent)
+        else:
+            path = Path(blender_path)
+
+        return path.as_posix()
+
     @classmethod
     def get_default_selection_keypmap(cls):
         """keymap to replicate default blender selection behaviour with click and box selection"""

src/blenderbim/blenderbim/tool/loader.py

@@ -191,16 +191,27 @@ class Loader(blenderbim.core.tool.Loader):
             mode = texture.get("Mode", None)
             node = None
 
-            if texture["type"] == "IfcImageTexture":
-                image_url = texture["URLReference"]
-                ifc_path = tool.Ifc.get_path()
-                if ifc_path:
-                    image_url = bpy.path.abspath(image_url, start=Path(ifc_path).parent)
+            if texture["type"] != "IfcImageTexture":
+                print(f"WARNING. Texture of type {texture['type']} is not currently supported, it will be skipped.")
+                continue
 
-            if not os.path.exists(image_url):
+            original_image_url = texture["URLReference"]
+            is_relative = not os.path.isabs(original_image_url)
+            image_url = Path(original_image_url)
+            if is_relative:
+                ifc_path = Path(tool.Ifc.get_path())
+                image_url = ifc_path.parent / image_url
+
+            # import pdb; pdb.set_trace()
+            if not image_url.exists():
                 print(f"WARNING. Couldn't find texture by path {image_url}, it will be skipped.")
                 continue
 
+            # keep url relative if it was before
+            image_url = str(image_url)
+            if is_relative and bpy.data.filepath:
+                image_url = bpy.path.relpath(image_url)
+
             if reflectance_method in ["PHYSICAL", "NOTDEFINED"]:
                 bsdf = tool.Blender.get_material_node(blender_material, "BSDF_PRINCIPLED")
                 if mode == "NORMAL":

src/blenderbim/blenderbim/tool/style.py

@@ -143,13 +143,10 @@ class Style(blenderbim.core.tool.Style):
             path = getattr(props, prop_name)
             if not path:
                 continue
-            if not os.path.abspath(path) and tool.Ifc.get_path():
-                path = os.path.join(os.path.dirname(tool.Ifc.get_path()), path)
-
             texture_data = {
                 "Mode": prop_mode,
                 "type": "IfcImageTexture",
-                "URLReference": path,
+                "URLReference": tool.Blender.blender_path_to_posix(path),
             }
             textures.append(texture_data)
 

src/ifcopenshell-python/ifcopenshell/api/style/add_surface_textures.py

@@ -130,12 +130,14 @@ class Usecase:
             return self.create_surface_texture(links[0].from_node, "DIFFUSE")
 
     def create_surface_texture(self, node, mode):
+        import blenderbim.tool as tool
+
         texture = self.file.create_entity(
             "IfcImageTexture",
             RepeatS=node.extension == "REPEAT",
             RepeatT=node.extension == "REPEAT",
             Mode=mode,
-            URLReference=node.image.filepath,
+            URLReference=tool.Blender.blender_path_to_posix(node.image.filepath),
         )
         self.textures.append(texture)
         self.process_texture_coordinates(node, texture)