太阳系三体模拟器

bodies/body.py

@@ -353,7 +353,11 @@ class Body(metaclass=ABCMeta):
         with open(json_file, "r", encoding='utf-8') as read_content:
             json_data = json.load(read_content)
             for body_data in json_data["bodies"]:
-                # print(body_data)
+                try:
+                    body_data = Body.exp(body_data)  # print(body_data)
+                except Exception as e:
+                    err_msg = f"{json_file} 格式错误：" + str(e)
+                    raise Exception(err_msg)
                 body = Body(**body_data)
                 bodies.append(body)
             if "params" in json_data:
@@ -361,6 +365,29 @@ class Body(metaclass=ABCMeta):
                 # print(body.position_au())
         return bodies, params
 
+    @staticmethod
+    def exp(body_data):
+        """
+        进行表达式分析，将表达式改为eval执行后的结果
+        :param body_data:
+        :return:
+        """
+        #
+        for k in body_data.keys():
+            v = body_data[k]
+            if isinstance(v, str):
+                if v.startswith("$exp:"):
+                    exp = v[5:]
+                    body_data[k] = eval(exp)
+            elif isinstance(v, list):
+                for idx,item in  enumerate(v):
+                    if isinstance(item, str):
+                        if item.startswith("$exp:"):
+                            exp = item[5:]
+                            v[idx] = eval(exp)
+
+        return body_data
+
 
 if __name__ == '__main__':
     # build_bodies_from_json('../data/sun.json')

data/tri_bodies_sim_perfect_03.json

@@ -5,11 +5,11 @@
       "mass": 2e+30,
       "init_position": [
         0.0,
-        518222240.0,
+        "$exp:math.sqrt(3) * 2 * AU",
         0.0
       ],
       "init_velocity": [
-        -14.890000343322754,
+        -14.89,
         0.0,
         0.0
       ],
@@ -27,13 +27,13 @@
       "name": "绿轨太阳B",
       "mass": 2e+30,
       "init_position": [
-        -299195744.0,
+        "$exp: -2 * AU",
         0.0,
         0.0
       ],
       "init_velocity": [
-        7.445000171661377,
-        -12.895118713378906,
+        "$exp: 1/2 * 14.88",
+        "$exp:-math.sqrt(3) / 2 * 14.88",
         0.0
       ],
       "density": 1408.0,
@@ -50,13 +50,13 @@
       "name": "蓝轨太阳C",
       "mass": 2e+30,
       "init_position": [
-        299195744.0,
+        "$exp: 2 * AU",
         0.0,
         0.0
       ],
       "init_velocity": [
-        7.445000171661377,
-        12.895118713378906,
+        "$exp: 1/2 * 14.88",
+        "$exp:math.sqrt(3) / 2 * 14.88",
         0.0
       ],
       "density": 1408.0,

scenes/ursina_json_sim.py

@@ -13,7 +13,7 @@ from scenes.func import ursina_run
 
 if __name__ == '__main__':
     # TODO: 去掉注释，太阳演示
-    bodies, params = Body.build_bodies_from_json('../data/sun.json')
+    # bodies, params = Body.build_bodies_from_json('../data/sun.json')
     # TODO: 去掉注释，太阳和地球演示
     # bodies, params = Body.build_bodies_from_json('../data/sun_earth.json')
     # TODO: 去掉注释，在地球上看月相演示变化过程演示