bim.flip_object #3803

Added new operator bim.flip_object that flips the object by flipping two of its axes and keeps the original placement.

Currently it can be found either from F3 search or from Shift-F hotkey for IfcBeam and IfcColumn in BIM tools.

src/blenderbim/blenderbim/bim/module/geometry/__init__.py

@@ -23,6 +23,7 @@ classes = (
     operator.AddRepresentation,
     operator.CopyRepresentation,
     operator.EditObjectPlacement,
+    operator.FlipObject,
     operator.GetRepresentationIfcParameters,
     operator.OverrideDelete,
     operator.OverrideDuplicateMove,

src/blenderbim/blenderbim/bim/module/geometry/operator.py

@@ -1723,3 +1723,19 @@ class OverrideModeSetObject(bpy.types.Operator):
         if self.edited_objs:
             return context.window_manager.invoke_props_dialog(self)
         return self.execute(context)
+
+
+class FlipObject(bpy.types.Operator):
+    bl_idname = "bim.flip_object"
+    bl_label = "Flip Object"
+    bl_description = "Flip object's local axes, keep the position"
+    bl_options = {"REGISTER", "UNDO"}
+
+    flip_local_axes: bpy.props.EnumProperty(
+        name="Flip Local Axes", items=(("XY", "XY", ""), ("YZ", "YZ", ""), ("XZ", "XZ", "")), default="XY"
+    )
+
+    def execute(self, context):
+        for obj in context.selected_objects:
+            tool.Geometry.flip_object(obj, self.flip_local_axes)
+        return {"FINISHED"}

src/blenderbim/blenderbim/bim/module/model/opening.py

@@ -393,18 +393,7 @@ class FlipFill(bpy.types.Operator, tool.Ifc.Operator):
             element = tool.Ifc.get_entity(obj)
             if not element or not element.FillsVoids:
                 continue
-
-            flip_matrix = Matrix.Rotation(pi, 4, "Z")
-
-            bottom_left = obj.matrix_world @ Vector(obj.bound_box[0])
-            top_right = obj.matrix_world @ Vector(obj.bound_box[6])
-            center = obj.matrix_world.translation.copy()
-            center_offset = center - bottom_left
-            flipped_center = top_right - center_offset
-
-            obj.matrix_world = obj.matrix_world @ flip_matrix
-            obj.matrix_world.translation.xy = flipped_center.xy
-            bpy.context.view_layer.update()
+            tool.Geometry.flip_object(obj, "XY")
         return {"FINISHED"}
 
 

src/blenderbim/blenderbim/bim/module/model/workspace.py

@@ -358,6 +358,7 @@ class BimToolUI:
                     cls.layout.operator("bim.mep_connect_elements")
             else:
                 add_layout_hotkey_operator(cls.layout, "Edit Axis", "A_E", "")
+                add_layout_hotkey_operator(cls.layout, "Flip", "S_F", bpy.ops.bim.flip_object.__doc__)
                 add_layout_hotkey_operator(cls.layout, "Butt", "S_T", "")
                 add_layout_hotkey_operator(cls.layout, "Mitre", "S_Y", "")
                 add_layout_hotkey_operator(cls.layout, "Rotate 90", "S_R", bpy.ops.bim.rotate_90.__doc__)
@@ -668,6 +669,8 @@ class Hotkey(bpy.types.Operator, tool.Ifc.Operator):
             bpy.ops.bim.flip_wall()
         elif self.active_class in ("IfcWindow", "IfcWindowStandardCase", "IfcDoor", "IfcDoorStandardCase"):
             bpy.ops.bim.flip_fill()
+        elif self.active_class in ("IfcBeam", "IfcColumn"):
+            bpy.ops.bim.flip_object(flip_local_axes="XZ")
         elif self.active_class in ("IfcDuctSegment", "IfcPipeSegment", "IfcCableCarrierSegment", "IfcCableSegment"):
             bpy.ops.bim.fit_flow_segments()
 

src/blenderbim/blenderbim/tool/blender.py

@@ -343,6 +343,8 @@ class Blender:
             "max_y": bound_box[6][1],
             "min_z": bound_box[0][2],
             "max_z": bound_box[6][2],
+            "min_point": Vector(bound_box[0]),
+            "max_point": Vector(bound_box[6]),
             "center": (Vector(bound_box[6]) + Vector(bound_box[0])) / 2,
         }
         return bbox_dict

src/blenderbim/blenderbim/tool/geometry.py

@@ -28,7 +28,7 @@ import blenderbim.core.style
 import blenderbim.core.spatial
 import blenderbim.tool as tool
 import blenderbim.bim.import_ifc
-from math import radians
+from math import radians, pi
 from mathutils import Vector, Matrix
 from blenderbim.bim.ifc import IfcStore
 
@@ -641,3 +641,25 @@ class Geometry(blenderbim.core.tool.Geometry):
     @classmethod
     def get_model_representations(cls):
         return tool.Ifc.get().by_type("IfcShapeRepresentation")
+
+    @classmethod
+    def flip_object(cls, obj, flip_local_axes):
+        assert len(flip_local_axes) == 2, "flip_local_axes must be two axes to flip"
+        rotation_axis = next(i for i in "XYZ" if i not in flip_local_axes)
+        rotation_axis_i = "XYZ".index(rotation_axis)
+
+        bb_data = tool.Blender.get_object_bounding_box(obj)
+        # min max points of rotated plane of origin based bounding box
+        min_point = Vector([min(i, 0) for i in bb_data["min_point"]])
+        max_point = Vector([max(i, 0) for i in bb_data["max_point"]])
+        # keep it in rotated plane only
+        max_point[rotation_axis_i] = min_point[rotation_axis_i]
+
+        # to compensate for flipped two axes
+        # we adjust new max point to match previous min point (or vice versa)
+        original_min_point = obj.matrix_world @ min_point
+        obj.matrix_world = obj.matrix_world @ Matrix.Rotation(pi, 4, rotation_axis)
+        new_max_point = obj.matrix_world @ max_point
+        obj.matrix_world.translation += original_min_point - new_max_point
+
+        bpy.context.view_layer.update()