object_print3d_utils/__init__.py

@@ -134,9 +134,9 @@ class SceneProperties(PropertyGroup):
         min = 0.01,
         subtype = 'DISTANCE',
         )
-    hollow_join: BoolProperty(
-        name = "Join",
-        description = "Join the generated offset mesh to the original object, effectively hollowing it",
+    hollow_create: BoolProperty(
+        name = "Create Hollow Copy",
+        description = "Create a hollow copy of the target object, with applied modifiers and scale",
         default = False
         )
 

object_print3d_utils/operators.py

@@ -843,9 +843,9 @@ class MESH_OT_print3d_hollow(Operator):
         min = 0.01,
         subtype = 'DISTANCE',
         )
-    join: BoolProperty(
-        name = "Join",
-        description = "Join the generated offset mesh to the original object, effectively hollowing it",
+    create_hollow: BoolProperty(
+        name = "Create Hollow Copy",
+        description = "Create a hollow copy of the target object, with applied modifiers and scale",
         default = False
         )
 
@@ -856,11 +856,15 @@ class MESH_OT_print3d_hollow(Operator):
         if not self.offset:
             return {'FINISHED'}
 
-        # Target object
+        # Get target mesh with modifiers
         obj = context.active_object
         depsgraph = context.evaluated_depsgraph_get()
         mesh_target = bpy.data.meshes.new_from_object(obj.evaluated_get(depsgraph))
-        mesh_target.transform(obj.matrix_world)
+
+        # Apply scale, but avoid translating the mesh
+        mat = obj.matrix_world.copy()
+        mat.translation = 0, 0, 0
+        mesh_target.transform(mat)
 
         # Read mesh to numpy arrays
         nverts = len(mesh_target.vertices)
@@ -888,13 +892,15 @@ class MESH_OT_print3d_hollow(Operator):
         obj_offset = bpy.data.objects.new(obj.name + ' offset', mesh_offset)
         bpy.context.collection.objects.link(obj_offset)
 
-        if not self.join:
+        if not self.create_hollow:
             # For some reason OpenVDB has inverted normals
             mesh_offset.flip_normals()
+            # Translate surface object to target object's position
+            obj_offset.matrix_world.translation = obj.matrix_world.translation
             # This mesh will not be used anymore
             bpy.data.meshes.remove(mesh_target)
         else:
-            # Create a copy of the target object with applied modifiers, scale
+            # Create a copy of the target object with applied modifiers and scale
             obj_hollow = bpy.data.objects.new(obj.name + " hollow", mesh_target)
             bpy.context.collection.objects.link(obj_hollow)
             if self.offset < 0.0:
@@ -913,6 +919,9 @@ class MESH_OT_print3d_hollow(Operator):
             context.view_layer.objects.active = obj_hollow
             bpy.ops.object.join()
 
+            # Translate hollow object to target object's position
+            obj_hollow.matrix_world.translation = obj.matrix_world.translation
+
 
         return {'FINISHED'}
 
@@ -920,7 +929,7 @@ class MESH_OT_print3d_hollow(Operator):
         print_3d = context.scene.print_3d
         self.offset = print_3d.hollow_offset
         self.resolution = print_3d.hollow_resolution
-        self.join = print_3d.hollow_join
+        self.create_hollow = print_3d.hollow_create
         if context.mode == 'EDIT_MESH':
             bpy.ops.object.mode_set(mode='OBJECT')
 

object_print3d_utils/ui.py

@@ -120,7 +120,7 @@ class VIEW3D_PT_print3d_transform(View3DPrintPanel, Panel):
         row.prop(print_3d, "use_alignxy_face_area")
         layout.label(text="Hollow")
         col = layout.column(align=True)
-        col.prop(print_3d, "hollow_join")
+        col.prop(print_3d, "hollow_create")
         col.prop(print_3d, "hollow_offset")
         col.prop(print_3d, "hollow_resolution")
         col.operator("mesh.print3d_hollow", text="Create Offset Surface")