add goal training

examples/pybullet/gym/pybullet_envs/deep_mimic/env/goals.py

@@ -0,0 +1,76 @@
+from enum import Enum
+import random
+import math
+
+def randomVal(lowerBound, upperbound):
+    difference = upperbound - lowerBound
+    return lowerBound + random.random() * difference
+
+class GoalType(Enum):
+    NoGoal = 0
+    Strike = 1
+    TargetHeading = 2
+    Throw = 3
+    TerrainTraversal = 4
+
+    @staticmethod
+    def from_str(goal_type_str):
+        if goal_type_str == '':
+            return GoalType.NoGoal
+        else:
+            try:
+                return GoalType[goal_type_str]
+            except:
+                raise NotImplementedError
+
+class Goal:
+    def __init__(self, goal_type: GoalType):
+        self.goal_type = goal_type
+        self.generateGoalData()
+
+    def generateGoalData(self):
+        if self.goal_type == GoalType.NoGoal:
+            self.goal_data = []
+
+        elif self.goal_type == GoalType.Strike:
+            # distance, height, rot
+            distance = randomVal(0.6, 0.8)
+            height = randomVal(0.8, 1.25)
+            rot = randomVal(-1, 1) # radians
+            
+            self.is_hit = False
+            self.is_hit_prev = False
+            # The max distance from the target counting as a hit
+            self.hit_range = 0.2
+
+            # Transform to xyz coordinates for placement in environment
+            x = distance * math.cos(rot)
+            y = distance * math.sin(rot)
+            z = height
+
+            # Y axis up, z axis in different direction
+            self.goal_data = [-x, z, y]
+
+        elif self.goal_type == GoalType.TargetHeading:
+            # Direction: 2D unit vector
+            # speed: max speed
+            random_rot = random.random() * 2 * math.pi
+            x = math.cos(random_rot)
+            y = math.sin(random_rot)
+            velocity = randomVal(0, 0.5)
+            self.goal_data = [x, y, velocity]
+
+        elif self.goal_type == GoalType.Throw:
+            # TODO
+            raise NotImplementedError
+        elif self.goal_type == GoalType.TerrainTraversal:
+            # TODO
+            raise NotImplementedError
+
+    def getTFData(self):
+        if self.goal_type == GoalType.Strike:
+            x = 0.0
+            if self.is_hit:
+                x = 1.0
+            return [x] + self.goal_data
+