scripts-blender/addons/brushstroke_tools/ops.py

@@ -495,6 +495,46 @@ class BSBST_OT_select_surface(bpy.types.Operator):
 
         return {"FINISHED"}
 
+class BSBST_OT_assign_surface(bpy.types.Operator):
+    """
+    Assign a surface object for the active context brushstrokes.
+    """
+    bl_idname = "brushstroke_tools.assign_surface"
+    bl_label = "Assign Surface"
+    bl_description = "Assign a surface object for the active context brushstrokes"
+    bl_options = {"REGISTER", "UNDO"}
+
+    surface_object: bpy.props.StringProperty()
+
+    @classmethod
+    def poll(cls, context):
+        settings = context.scene.BSBST_settings
+        return bool(settings.context_brushstrokes)
+
+    def execute(self, context):
+        bs_ob = utils.get_active_context_brushstrokes_object(context)
+        if not bs_ob:
+            return {"CANCELLED"}
+        
+        surface_object = bpy.data.objects.get(self.surface_object)
+
+        if not surface_object:
+            return {"CANCELLED"}
+
+        utils.set_surface_object(bs_ob, surface_object)
+        return {"FINISHED"}
+
+    def draw(self, context):
+        layout = self.layout
+        layout.prop_search(self, 'surface_object', bpy.data, 'objects')
+
+    def invoke(self, context, event):
+        bs_ob = utils.get_active_context_brushstrokes_object(context)
+        surf_ob = utils.get_surface_object(bs_ob)
+        if surf_ob:
+            self.surface_object = surf_ob.name
+        return context.window_manager.invoke_props_dialog(self)
+
 def set_brushstrokes_deformable(bs_ob, deformable):
     flow_ob = utils.get_flow_object(bs_ob)
 
@@ -1039,6 +1079,7 @@ classes = [
     BSBST_OT_copy_flow,
     BSBST_OT_switch_deformable,
     BSBST_OT_select_surface,
+    BSBST_OT_assign_surface,
     BSBST_OT_init_preset,
     BSBST_OT_make_preset,
     BSBST_OT_preset_add_mod,

scripts-blender/addons/brushstroke_tools/ui.py

@@ -300,6 +300,8 @@ class BSBST_MT_bs_context_menu(bpy.types.Menu):
 
         op = layout.operator('brushstroke_tools.copy_flow')
 
+        op = layout.operator("brushstroke_tools.assign_surface")
+
 class BSBST_PT_brushstroke_tools_panel(bpy.types.Panel):
     bl_space_type = 'VIEW_3D'
     bl_region_type = 'UI'

scripts-blender/addons/brushstroke_tools/utils.py

@@ -458,10 +458,15 @@ def get_surface_object(bs):
         return None
     return bs['BSBST_surface_object']
 
-def set_surface_object(bs, ob):
+def set_surface_object(bs, surf_ob):
     if not bs:
         return
+    objects = [bs]
+    flow_ob = get_flow_object(bs)
+    if flow_ob:
+        objects += [flow_ob]
     # assign surface pointer
+    for ob in objects:
         for mod in bs.modifiers:
             mod_info = bs.modifier_info.get(mod.name)
             if not mod_info:
@@ -471,14 +476,16 @@ def set_surface_object(bs, ob):
                     continue
                 if not s.link_context_type == 'SURFACE_OBJECT':
                     continue
-            mod[s.name] = ob
-    ob.update_tag()
+                mod[s.name] = surf_ob
+        ob.parent = surf_ob
+        ob.parent_type = 'OBJECT'
+    surf_ob.update_tag()
 
     if bs.type == 'CURVES':
-        bs.data.surface = ob
-        bs.data.surface_uv_map = ob.data.uv_layers.active.name
+        bs.data.surface = surf_ob
+        bs.data.surface_uv_map = surf_ob.data.uv_layers.active.name
 
-    bs['BSBST_surface_object'] = ob
+    bs['BSBST_surface_object'] = surf_ob
 
 def get_flow_object(bs):
     if not bs: