太阳系三体模拟器

bodies/asteroids.py

@@ -29,7 +29,9 @@ class Asteroids(Body):
     def __init__(self, name="Asteroids", mass=1.9891e30,
                  init_position=[0, 0, 0],
                  init_velocity=[0, 0, 0],
-                 texture="asteroids.png", size_scale=1.0, distance_scale=1.0,rotation_speed=0.6130):
+                 texture="asteroids.png", size_scale=1.0,
+                 distance_scale=1.0, rotation_speed=0.6130,
+                 parent=None):
         params = {
             "name": name,
             "mass": mass,
@@ -40,7 +42,8 @@ class Asteroids(Body):
             "texture": texture,
             "size_scale": size_scale,
             "distance_scale": distance_scale,
-            "rotation_speed": rotation_speed
+            "rotation_speed": rotation_speed,
+            "parent": parent
         }
         super().__init__(**params)
         # 环状星群

bodies/body.py

@@ -21,7 +21,7 @@ class Body(metaclass=ABCMeta):
     def __init__(self, name, mass, init_position, init_velocity,
                  density=5e3, color=(125 / 255, 125 / 255, 125 / 255),
                  texture=None, size_scale=1.0, distance_scale=1.0,
-                 rotation_speed=None):
+                 rotation_speed=None, parent=None):
         """
         天体类
         :param name: 天体名称
@@ -70,6 +70,7 @@ class Body(metaclass=ABCMeta):
 
         # 是否显示
         self.appeared = True
+        self.parent = parent
 
     @property
     def has_rings(self):

scenes/solar_system_2.py

@@ -22,12 +22,13 @@ if __name__ == '__main__':
     #  2、为了达到最佳的显示效果，对每个行星天体的距离进行了缩放
 
     # region 构建太阳系
+    sun = Sun(size_scale=0.8e2)
     bodies = [
-        Sun(size_scale=0.8e2),                              # 太阳放大 80 倍
+        sun,                                                # 太阳放大 80 倍
         Mercury(size_scale=4e3, distance_scale=1.3),        # 水星放大 4000 倍，距离放大 1.3 倍
         Venus(size_scale=4e3, distance_scale=1.3),          # 金星放大 4000 倍，距离放大 1.3 倍
         Earth(size_scale=4e3, distance_scale=1.3),          # 地球放大 4000 倍，距离放大 1.3 倍
-        Asteroids(size_scale=3e2),  # 小行星模拟
+        Asteroids(size_scale=3e2, parent=sun),              # 小行星模拟
         Mars(size_scale=4e3, distance_scale=1.3),           # 火星放大 4000 倍，距离放大 1.3 倍
         Jupiter(size_scale=0.68e3, distance_scale=0.65),    # 木星放大 680 倍，距离缩小到真实距离的 0.65
         Saturn(size_scale=0.68e3, distance_scale=0.52),     # 土星放大 680 倍，距离缩小到真实距离的 0.52

simulators/simulator.py

@@ -32,7 +32,7 @@ class Simulator(metaclass=ABCMeta):
         :return:
         """
         for body in self.bodies_sys.bodies:
-            view = viewer_type(body)
+            view = viewer_type(body, self.bodies_sys)
             self.body_views.append(view)
 
     def evolve(self, dt: int):
@@ -64,8 +64,8 @@ class Simulator(metaclass=ABCMeta):
 
             view.update()
 
-        self.bodies_sys.bodies = list(filter(lambda b:b.appeared, self.bodies_sys.bodies))
-        self.body_views = list(filter(lambda b:b.appeared, self.body_views))
+        self.bodies_sys.bodies = list(filter(lambda b: b.appeared, self.bodies_sys.bodies))
+        self.body_views = list(filter(lambda b: b.appeared, self.body_views))
 
     @abstractmethod
     def run(self, dt: int, **kwargs):

simulators/views/body_view.py

@@ -18,8 +18,9 @@ class BodyView(metaclass=ABCMeta):
     天体视图（天体效果展示用）
     """
 
-    def __init__(self, body: Body):
+    def __init__(self, body: Body, bodies_system):
         self.body = body
+        self.bodies_system = bodies_system
         self.sphere = None
         if self.body.texture is None or self.body.texture == '':
             self.color = tuple(np.array(body.color) / 255)

simulators/views/ursina_view.py

@@ -153,7 +153,7 @@ class Planet(Entity):
         try:
             pos = self.position
         except Exception as e:
-            self.destroy_me()
+            self.destroy_all()
             return
         trails_keys = self.trails.keys()
         # 如果有拖尾
@@ -193,10 +193,12 @@ class Planet(Entity):
 
     def turn(self):
         pos = self.body_view.position * UrsinaConfig.SCALE_FACTOR
-
-        self.x = -pos[1]
-        self.y = pos[2]
-        self.z = pos[0]
+        if self.body_view.body.parent is None:
+            self.x = -pos[1]
+            self.y = pos[2]
+            self.z = pos[0]
+        else:
+            self.follow_parent()
 
         dt = 0
         if hasattr(self.body_view.body, "dt"):
@@ -217,7 +219,7 @@ class Planet(Entity):
             # 天体旋转
             self.rotation_y -= self.rotspeed
         except Exception as e:
-            self.destroy_me()
+            self.destroy_all()
             return
 
         # 如果有行星环
@@ -231,6 +233,18 @@ class Planet(Entity):
         if len(self.body_view.body.his_position()) > 1:
             self.create_trails()
 
+
+    def follow_parent(self):
+        if not hasattr(self.body_view, "bodies_system"):
+            return
+        sys = self.body_view.bodies_system
+        for b in sys.bodies:
+            if self.body_view.body.parent == b:
+                pos = b.position * UrsinaConfig.SCALE_FACTOR
+                self.x = -pos[1]
+                self.y = pos[2]
+                self.z = pos[0]
+
     def create_rings(self):
         """
         创建行星环（使用土星贴图）
@@ -252,11 +266,17 @@ class Planet(Entity):
         # 设置行星环不受灯光影响，否则看不清行星环
         self.ring.set_light_off()
 
-    def destroy_me(self):
+    def destroy_all(self):
+        # 从天体系统中移除自己（TODO:暂时还不能移除）
+        # self.body_view.bodies_system.bodies.remove(self.body_view.body)
+
+        # 删除拖尾
         for entity, pos in self.trails.items():
             destroy(entity)
+        # 如果有行星环，则删除行星环
         if hasattr(self, "ring"):
             destroy(self.ring)
+        # 最后删除自己
         destroy(self)
 
 
@@ -265,8 +285,8 @@ class UrsinaView(BodyView):
     ursina天体视图（天体效果展示用）
     """
 
-    def __init__(self, body: Body):
-        BodyView.__init__(self, body)
+    def __init__(self, body: Body, bodies_system):
+        BodyView.__init__(self, body, bodies_system)
         self.velocity = body.velocity
 
         self.planet = Planet(self)
@@ -281,9 +301,9 @@ class UrsinaView(BodyView):
         """
         self.planet.turn()
 
-
     def appear(self):
         pass
 
     def disappear(self):
-        self.planet.destroy_me()
+        self.planet.destroy_all()
+        self.appeared = False