script: drop on surface

asset/config/default.json

@@ -4,7 +4,8 @@
         "bl_file_extensions": ".obj",
         "poll_area": "VIEW_3D",
         "operator_context": "EXEC_DEFAULT",
-        "foreach_post_script": "addCollection.py;printArgs.py;drop2floor.py;alignAxisX.py"
+        "foreach_post_script": "addCollection.py;printArgs.py",
+        "post_script": "dropOnSurface.py"
     },
     "Import Image Nodes": {
         "bl_file_extensions": ".png;.jpg",

asset/scripts/post_script/dropOnSurface.py

@@ -0,0 +1,30 @@
+import bpy
+from mathutils import Vector
+from cdi_tool.boundingBox import ObjectBoundingBox, ObjectsBoundingBox, C_OBJECT_TYPE_HAS_BBOX
+from cdi_tool.emptyParent import create_tmp_parent, apply_tmp_parent, align_obj2normal
+from cdi_tool.raycast import ray_cast, exclude_ray_cast
+
+event = globals().get('event')
+
+selected_objs = [obj for obj in bpy.context.selected_objects if obj.type in C_OBJECT_TYPE_HAS_BBOX]
+bboxs = [ObjectBoundingBox(obj, is_local=False) for obj in selected_objs]
+
+if len(bboxs) != 0:
+    objs_A = ObjectsBoundingBox(bboxs)
+    bottom = objs_A.get_bottom_center()
+    normal = Vector((0, 0, 1))
+    tmp_parent = create_tmp_parent(bottom, selected_objs)
+    bpy.context.view_layer.depsgraph.update()
+
+    with exclude_ray_cast(selected_objs):
+        result, target_obj, view_point, world_loc, normal, location, matrix = ray_cast(bpy.context, event)
+        if result:
+            normal = normal.normalized()
+            world_loc = location
+    # update deps
+    bpy.context.view_layer.depsgraph.update()
+    tmp_parent.location = world_loc
+    bpy.context.view_layer.depsgraph.update()
+    align_obj2normal(normal=normal, obj=tmp_parent)
+
+    apply_tmp_parent(tmp_parent, selected_objs)

modules/cdi_tool/emptyParent.py

@@ -0,0 +1,92 @@
+import bpy
+from mathutils import Vector
+
+
+def create_tmp_parent(bottom_loc: Vector, selected_objs: list[bpy.types.Object], axis='Z',
+                         invert_axis: bool = False)->bpy.types.Object:
+    offset = 0.001
+    if invert_axis: offset = -offset
+
+    empty = bpy.data.objects.new('Empty', None)
+    empty.name = 'TMP_PARENT'
+    empty.empty_display_type = 'PLAIN_AXES'
+    empty.empty_display_size = 0
+    empty.location = bottom_loc
+    z = getattr(empty.location, axis.lower())
+    setattr(empty.location, axis.lower(), z - offset)
+
+    rot_obj = bpy.context.object
+    empty.rotation_euler = rot_obj.rotation_euler
+
+    def create_tmp_parent(obj):
+        con = obj.constraints.new('CHILD_OF')
+        con.name = 'TMP_PARENT'
+        con.use_rotation_x = True
+        con.use_rotation_y = True
+        con.use_rotation_z = True
+        con.target = empty
+        obj.select_set(False)
+
+    for obj in selected_objs:
+        if obj.parent and obj.parent in selected_objs:
+            obj.select_set(False)
+            continue
+        # loop over the constraints in each object
+        create_tmp_parent(obj)
+    # if obj is not mesh
+    if rot_obj not in selected_objs:
+        create_tmp_parent(rot_obj)
+        rot_obj.select_set(True)
+
+    bpy.context.collection.objects.link(empty)
+    bpy.context.view_layer.objects.active = rot_obj
+    return empty
+
+
+def apply_tmp_parent(tmp_parent: bpy.types.Object, selected_objs: list[bpy.types.Object]):
+    if not tmp_parent: return
+
+    # apply constraints
+    def apply_const(obj):
+        obj.select_set(True)
+        tmp_mx = obj.matrix_world.copy()
+        for con in obj.constraints:
+            if con.name == 'TMP_PARENT' and con.type == 'CHILD_OF':
+                obj.constraints.remove(con)
+
+        obj.matrix_world = tmp_mx
+
+    for obj in selected_objs:
+        apply_const(obj)
+
+    if bpy.context.object not in selected_objs:
+        apply_const(bpy.context.object)
+
+    # remove empty
+    bpy.data.objects.remove(tmp_parent)
+
+
+def align_obj2normal(normal: Vector, obj: bpy.types.Object, axis: str = 'Z', invert_axis=False):
+    """清除除了local z以外轴向的旋转"""
+    v = -1 if invert_axis else 1
+    if axis == 'Z':
+        z = Vector((0, 0, v))
+    elif axis == 'Y':
+        z = Vector((0, v, 0))
+    else:
+        z = Vector((v, 0, 0))
+
+    rotate_clear = obj.matrix_local.to_quaternion()
+
+    for a in ['x', 'y', 'z']:
+        if a == axis.lower(): continue
+        # clear
+        setattr(rotate_clear, a, 0)
+
+    rotate_clear = rotate_clear.to_matrix()
+    try:
+        offset_q = z.rotation_difference(normal)
+    except:
+        offset_q = Vector((0, 0, 1)).rotation_difference(z)
+
+    obj.rotation_euler = (offset_q.to_matrix() @ rotate_clear).to_euler()